Tails was in his workshop testing out the energy of the chaos emeralds. Despite having vast amount of power and energy. We still don't know anything about them.  From what Shadow and Silver told him, the emeralds can actually warp time and space. The two-twin tailed fox was fascinated on what he can actually learn. He has done several test on the seven emeralds. Whether it's storing or releasing energy.  Since the emeralds can make portals to the past. The fox tries to test this and see this for himself.
Tails build a giant mechanism that was design to create and stabilize the energy's to make portals. It's not like he hasn't done anything like this before. Afterall building a gateway is child's play. Tails was at the control console. He had a whiteboard filled with complex calculations and a chalkboard with more math. With a simple press of the button, the machine will be activate. The young fox had been preparing all day for this. But even so, he was still nervous. He took a deep breath, before pressing the activation button. The emeralds were then released, and their energy was being harness by the machine.
The gateway activates gathering energy from the emeralds, so much energy and power was surging out. But soon enough the portal was able to stabilize and actually take form. "It worked! I can't believe it really worked." The twin tailed fox was in awe, and soon enough a grin appeared. This was it, the chance he's been waiting for. He can finally go to the past and see it with his own eyes. The portal was like a window, able to see what was on the other side. Tails was prepare for this with his tools so he couldn't be seen.
With everything set, the fox steps into the portal. As soon as he did, he felt a sense of vertigo. Like his body was spinning. This wasn't the first time he had ever used one of these. But it was the first time he actually felt this way. Tails could only keep his eyes closed and wait. Wait for the moment that everything stop.
The two-tailed fox wakes up in what appears to be Green Hill, since it had green grass... in reality Tails has never been to that place, even though Sonic has told him many wonders about that place. "Ouch, I knew this time travel thing wasn't going to be a nice, smooth ride." Then he realizes something too strange and that is that his voice was even higher than before, that's why he decides to check his body better and what a huge surprise it would be. "But what the hell!!!!!!".
The former male fox had become a girl, with nice curves, a round and soft butt, thinner arms and legs, also that her hair had grown and above all else she now had large C-cup breasts. "Okay okay, calm down Tails! I know there's a blessed scientific explanation for all this."
Tails was exploring more of his body wondering why he transform into the opposite sex. Maybe if he searched around a little bit more he can find out why. After all he's suppose to be in the past right?
As Tails explore the world this place which seems to be Green Hill. Everything seems the same, but wasn't this suppose to be the past? As she was flying through the air spinning her twin tails, something blue and fast zip passed her but then came right back. It was Sonic but...he was a girl?
"Hey Tails, I thought you were in your workshop, what are you doing in Green Hill?" The female Sonic asked Tails.
"S-Sonic...you're a girl?" Tails said in shock.
"Uhhh, yeah... always have been buddy... are you okay?" Sonic asked cocking an eyebrow.
"Uh...yeah, yeah... I'm fine..." Tails said trying to sound normal.
"Hmmm, okay, so are you going to answer my question?" Sonic asked once more.
"Huh? What question?" Tails said in confusion.
"Why are you in Green Hill, aren't you supposed to be in your workshop?" Sonic asked again.
"Oh... yeah, I was just going to run some errands, you know, stock up on supplies." The tails answered, it seemed Tails didn't travel into the past like he was planning to, but into another reality in of itself. Yet somehow his body adjusted into this reality becoming a woman. This was fascinating indeed.
"Yeah, well try not to stay too long, I'm gonna head over to Twinkle Park, I got a date with Jamie Rose."  Sonic said. 
"J-Jamie Rose?" Tails said shocked. "Yeah, I am surprised we didn't get kicked out or banned for having sex on one of the rides." The blue female hedgehog laughed then a realized something as she looked at the female fox. "Oh I almost forgot, Custard the rabbit wanted you to come over to his house."
"Oh...really?" Tails asked. "Yeah and don't worry his dad Vermont is out of the house, so you two can have all the fun you want.~" She teased Tails. Which made the fox blushed. But she doesn't know why because she doesn't know who this Custard person is, but if she is correct maybe it's Cream from this reality?
"ohhh... that's good, then I should go there, take care Sonic", said the fox, although basically she didn't know if that was 100% the name of the "Sonic" of this dimension.
"I'm going to do it! See you later Tailsko," she runs at full speed leaving behind a trail of dust.
The now Tailsko had to touch her face to avoid the dust bothering her
"No matter what dimension it is, this hedgehog always has that very extroverted attitude, well... I should go to that place"
So the little fox using her two tails propelled herself at full speed to the house of the so-called "Custard", although technically she didn't know where he lived, the two-tailed one sensed that he should be in the same place where her female counterpart/Crush lives.
Half an hour later, Tailsko had arrived at the rabbit family's house and at first glance it was almost the same as the one he knew in his dimension, only with a few small changes.
"Well, it's time to see what this version of Cream is like," the little fox knocks on the door, waiting patiently for it to open.
After a few seconds of waiting, the door opens to reveal a young rabbit.
"ohh, Hello Miss Tailsko, come in, I've been waiting for you hehehe,"  he was nervous because he was practically seeing the only girl who caught his heart since he was about 8 years old.
"ehhh.... thank you for your kindness" mysteriously I was nervous, although maybe it's because of being in this female body.
There Tailsko had entered the house and could see that inside it was different from the Cream's house from his dimension, since it felt like a more masculine atmosphere but without going to the exaggeration. But above all the most shocking change for the little fox was the same young rabbit that was in front of her. Custard wore a dark red shirt along with a blue bow tie, white shorts, although he had the same color sneakers as his female counterpart, in addition to having longer ears and a cute brown tuft. In itself, the young rabbit's appearance is more manly but still retains the same gentle and adorable attitude as his female version.
"Do you want to drink something?" Asked the young rabbit, who was still nervous because he was alone with Tailsko.
"Yes please, I'll have a glass of water," said the little fox, sitting on the couch, crossing her legs and resting her hands on them.
"Sure, coming right away, miss Tailsko." The male bunny walks over to the kitchen and gets the fox a glass of water, then goes back to Tailsko. Who ends up taking a few sips.
"Ummm Miss Tailsko, there's something I've been waiting to say. Something I've never had years to say until now..." Custard was blushing, it was a bit cute.
"Really, what is it, Custard?" Tailsko asks, finishing her glass.
"Miss Tailsko, I love you! Will you be my girlfriend?" Asked the young rabbit, the two-tailed fox was speechless, she couldn't believe the young rabbit had said those words, but above all she didn't understand why.
"Wow, that's really forward Custard." Tailsko said surprised.
"I know, I just can't hold back these feelings anymore. I really care about you and I want to be with you..." Custard confesses as he approaches Tailsko.
"Well... I... don't know..." Tailsko says blushing.
"Come on, we both know you want me." The young rabbit places his hand on Tailsko's thigh. "Your body is begging for my love."
The fox was speechless, this male version Cream was not the sweet and shy boy she thought. I mean the Cream he knew would never do this! Because she's very shy and timid girl. But I guess in this reality her male counterpart is more bold. 
As Custard continue to make advances towards the vixen, she felt her body become hot. She didn't feel like this before? Was it Custard's flirtation? But that couldn't be it because Tailsko can handle be flirted with, she started to feel wet between her legs. Feeling horny as a woman totally feels different but the same as being horny as a guy.
"You're getting wet, aren't you? You really want me, huh?"
"W-what... I-I don't."
"Don't deny it, come on let's make out~" As much as Tailsko wants to just push him away she can't fight it anymore.
"A-Alright..."
The young rabbit grabs Tailsko's face and begins to make out with her, their tongues wrestling. The fox was surprised but didn't resist, her body was reacting on its own. Tailsko was letting herself enjoy it.
The rabbit and vixen duo were enjoying this hot moment, especially Tailsko who basically let herself be groped by Custard's hands.
"Wait, we can continue kissing in your room, my cute bunny."
"Of course, my sexy little vixen."
The rabbit gets up to grab the little vixen princess style, although he had to be very careful not to drop her. There Custard took Tailsko straight to his room, where she left her on his bed.
"Aren't you going to close the door? What happens if Mr. Vermont shows up?"
"Don't worry, my dad went with Miss Victoria on a date, so we have all the time in the world."
"Oh, that's good, then..."
Custard approaches Tailsko, the two kiss once more. Their hands exploring each other's bodies. The fox couldn't help but feel how hard and big the young rabbit was. She couldn't help but get aroused and horny. She feels his erection through his white shorts, she couldn't believe she was about to do this. Tailsko only slept with Cream with their reality as a guy only a few times. But this one was so eager.
"Are you sure about this?" She asked him.
"I'm sure." He smiled.
"Then show me what you've got, handsome."
Custard takes off his red shirt and unbuttons his pants, revealing a 9 inch cock.
"Damn, how big is that?" Tailsko asks in surprise.
"It's nine inches, do you like it?"
"Yes, I love it, come on and fuck me." Tailsko couldn't believe she was acting this slutty. I mean where was this coming from. She never felt this horny ever in her life. Tailsko removed her clothing and revealed her naked body. Her breasts were a C-cup, and she had a tight little pussy.
"Wow, you're sexy," Custard said as he climbed onto the bed, his 9-inch dick pressing against the fox's pussy.
"Mmmmm, thanks," Tailsko moans as Custard's cock grinds against her wet pussy.
"I hope you're ready bitch, because you're going to feel my big carrot" He was more than excited
"Yes yes yes!! Come on my stud rabbit, be as rough as possible with this horny bitch"
In that Custard without further delay stuck his 9 inches of rabbit cock inside the bitch's pussy, there Tailsko's mind entered a completely new world of pleasure that his mind never thought existed, meanwhile the rabbit gave strong thrusts and at the same time sucked one of the bitch's breasts which consequently made her moan with pleasure. About 5 minutes had passed, but for Tailsko it was like hours, he had never imagined that female pleasure was absurdly incredible and he would love to spend more time in this dimension.... Until the most important moment would arrive.
"My god Tailsko, you're so tight..." she breathed heavily "I'm going to cum inside you and fill you with all my rabbit cum."
If Tailsko had even the slightest inkling of clear thinking she would have said no, but that was long gone.
"Do it Custard!! I want to have our offspring inside me!" she screamed with great excitement and placing her legs around the rabbit's waist so he couldn't get out.
Custard's bed starts to rock back and forth as he starts to the vixen. She can feel his strong dick enter her stretching her walls. Being fucked as a girl felt so new and different. I mean sure in her usually normal male body Tails got a dick up his ass once or twice. But this was a whole new level. Custard's dick was traveling so deep inside practically hitting her cervix. It was painful but awesome!
The young rabbit was pounding his hips into the vixen's, their bodies making contact. Tailsko's body was in heat, she was enjoying it so much. Her tail was wagging uncontrollably, showing that she was enjoying it.
"F-Fuck...you're amazing Custard!~" She moaned.
"Y-You're pretty amazing too Tailsko." He smiled as his dick slammed against her walls.
"H-Hey...I want to taste your cock, it's a nice treat." Tailsko smiled as she stopped him and pushed him off of her. Custard fell on his back onto his bed. She began to stroke his throbbing dick with her hands, licking the tip and sucking on the sides.
"Oh fuck, yes...that feels amazing." He moaned.
Tailsko took his whole length down her throat, gagging as his dick reached the back of her throat.
"Oh yes, suck it harder..." He grunted as he held the back of her head.
The vixen sucked his dick as hard as she could, bobbing her head up and down. Her hands were also playing with his balls as well. Custard could feel his release coming.
"Shit, I'm gonna cum!" He exclaimed.
She pulled her mouth off his dick. "Not yet, you're gonna fuck my tits first." She smiled as she laid on her back, her tits exposed. Custard stood up and climbed onto her. He put his dick between her tits, and squeezed her boobs around his dick. He starts to thrust his hips back and forth feeling her soft chest around his dick. The tip of his cock meets her lips and Tailsko either licks the head or gives it a a quick kiss. Her lips are covered in precum in the process.
Custard never thought the aphrodisiac would work so well, he really doubted if the gift his father gave him would work but it completely exceeded his expectations, now he was close to releasing all his essence on his beloved's tits again.
"Ah no no no, naughty bunny, now that I've had my fun with that huge cock of yours, let's go back to where we left off" said Tailsko with a half evil smile.
"but, I really need..." but the rabbit is interrupted when the vixen put a finger in his mouth so he keeps a moment of silence.
"And you're going to do it my impatient bunny... But we'll do it fox style" said Tailsko with a strange glint of determination.
The vixen releases her boyfriend's cock from her tits and she herself gets on all fours moving her two long tails making her look sexier than she already was before.
"Come on Custard, show me how rough a rabbit can be with a very horny slut" Tailsko said wanting to be dominated.
There Custard breathed in and out deeply for this very important moment in his young life.
" You're going to wish you hadn't said those words, little slut* -He smiles as he gets on his knees to place his cock in the only hole he hadn't tried yet... Tailsko's little ass, as he penetrated the slut's slammed hole, she screamed in pleasure and her tails stood up because of this, although she had already felt this before, being in a girl's body changed everything, the rabbit without thinking much gave strong and fast thrusts while giving a couple of blows to the two-tailed's ass that only made her even hornier.
"Oh my god yes! Yes, that's it! Fuck me hard and fast, my little rabbit slut!"
Tailsko could hear his boyfriend grunting and panting behind her. She could feel his big dick inside her, stretching her asshole wide open. She was loving it.
"Oh yes! You're so fucking tight!" He slammed his dick in and out of her ass. Her ass was so much tighter with her pussy. He can feel the walls squeezing him more increasing the amazing sensation he was going through.
"God you're so good. You're such a sexy bitch." Custard said as his dick kept moving inside her.
"Yes! Keep calling me that!"
"Oh, I didn't know you were such a slut."
"Fuck yeah, I'm a fucking slut!"
"I bet you want more don't you?"
"Yes, give me more! I want more!"
"That's right, take it all! Take it all, you little whore!"
"Ohhh yessss, fuck me hard Custard!~" Tailsko yelled
"You want to get fucked, huh? Well, I'll give you something to remember this." He grabbed her two tails, making them look like handles.
"YES YES! FUCK ME HARDER CUSTARD! YOU'RE THE BEST BUNNY SLUT I'VE EVER HAD!~" Tailsko couldn't contain her screams.
"Yes! Tell everyone how much you love my cock!"
"OH MY GOD, IT FEELS SO GOOD! IT'S SO BIG, FUCK ME WITH YOUR RABBIT COCK!"
There bodies slammed together and his room was echoing off the slap of sex. His balls keeps slapping her ass. Sweat ran down their bodies, and Custard kept holding a firm grip on her tails as he fucked her from behind.
"God damn Tailsko, your ass is so tight!"
"Yes! Fuck me hard and fast you stupid rabbit!!!"
"I'll fuck you until you can't walk straight for a week, bitch!"
"Oh my god, that sounds amazing, please, fuck me until I can't walk."
"Fuck yes, I'll pound you all night long."
This was everything that the rabbit could've of hoped for as he was on cloud 9. This was the best day of his life.
"OHHH FUCK! I'M GONNA CUM, I'M GONNA CUM!!" He announced.
"Oh yes, cum inside me!! I want you to cum inside my pussy!!!"
"FUCK, HERE IT COMES!
"AHHHHHH, YEEEEEESSSSS!!!" She screams begging for it. She feels him switch holes and once again dive deep in her front entrance. He released all his warm cum inside her, she could feel him shooting rope after rope of his thick warm cum deep inside her. Tailsko was in pure bliss as she was filled up. His seed was painting the inside of her white. She also came on Custard's cock, as she squirted her fluids that covered his abdomen.
"Ah, that was amazing, you little rabbit whore. You came inside me. Ohhh, I'm so full."
"That's right, you're filled with my cum." He smiled.
The rabbit pulled his cock out of the bitch's ass leaving behind a pile of fresh and fertile semen all over her ass and also on top of the bed sheets. They had both fallen on top of each other.
"Wow... you really were very hard"-Tailsko said
"hehehe, sorry, but I really always dreamed of doing this"- said Custard
"how long have we been talking?"
"Well... let's say since I reached adolescence"
"Ohhhh, so since then you have wanted this body?
"Yes, although as you already know, I had already fallen in love with you a long time ago"
There Tailsko would notice that he still felt Custard's cock still hard as a rock, apparently the theory that rabbits had extreme durability was not an exaggeration.
"By Chaos!!! You bunnies don't get tired??"
"Hehehe, what can I say, being with you makes me way more excited than you can imagine"
"So... you still want to leave your semen inside my hungry pussy?"
"You can bet on your soft tails that you do!"
"A little bet, the first one to get tired, must be the winner's servant for a week, do you accept bunny?"
"It's a challenge accepted, I can already imagine seeing you dressed in a cute maid outfit"
Both characters looked at each other with such enormous lust that only they would end up surrounded by fluids...
Time passes as both fox and rabbit go round after round. Tailsko had to admit that having sex as a girl was much better, she was able to orgasm several times, and the best of all is that the rabbit's stamina is almost limitless. The young fox is completely exhausted, Custard is standing next to her bed, looking at her and smiling.
"Are you sure you're tired Tailsko?" He asked panting wiping the sweat off his forehead.
"Oh... I'm done... I'm completely satisfied." She said breathing heavily, her breasts were rising and falling with each breath.
"And that settles that, I'm the winner!" He shouted with excitement.
"Hehe, yes... although you will have to wait for my energy to recharge, since it is clear that I have lost, not only is my body tired, but also my mind"
"Well, I hope you can rest, because starting tomorrow you are my personal maid for the week, remember"
"Yeah, yeah, now give me a break, you little pervert" She smirked feeling her heavy eyelids.
"Hahaha, as you wish, my future wife, but remember, we will have to marry someday" He smirked looking at her.
"I'll think about it, now stop looking at my naked body and let me sleep." She shuts her eyes.
"As you wish, honey" Custard leans down and kisses her forehead, before getting in the bed and cuddling up next to her.
Tailsko, with the little strength she had left, embraces her beloved rabbit who was already sleeping tenderly like an angel.
Although the little fox had her doubts about really staying here in this dimension, her heart told her that the best decision is to be here with a boy who truly loves and respects her.
"Later I will ask him why he acts like that, but first it's time to take a well-deserved nap" answered the little fox to finally be able to sleep with her beloved in the realm of dreams.
But without her knowing it, inside her it was happening that one of Custard's sperm managed to find a fertile egg that finally managed to enter inside her... Very possibly the subject of the wedding will have to be brought forward a little. But that would be a story for another day.