Describe Gadget Hackwrench:
(1989) Small, cute, and fuzzy. The little mouse is an amazing tinkerer, her tiny hands and tools able to put together, or disassemble, any machine. She is prone to gaining weight, and has an insatiable sex drive.
(1990) She's a cute, spunky, female mouse who loves a challenge and hates to lose. She can be very sweet, especially when horny. But she has a fiery temper when she's not sexually satisfied, and this causes her to grow and gain weight faster. 
(1991) Gadget is very friendly, cheerful and full of optimism. She's always ready to take on a new challenge. Able to make things most wouldn't even think possible, and has the ability to make things no one has ever thought of. Gadget can get quite carried away, and is easily distracted. Her body has continued to increase in sensitivity and fertility, and she almost always sports a prominent plump belly.
(1992) Gadget is a kind, intelligent, and beautiful young mouse. Her body and mind continue to become more fertile and sensitive; she is often drunk on her own hormones. She is still a skilled inventor, but often prefers to take the perverted role in sex. Growing her belly and becoming fatter is an enormous turn-on for her.
(1993) Gadget's brain chemistry has been altered, making her incredibly horny. Her belly and breasts are both larger, and she is still becoming fatter. She can no longer focus on inventing, but has a talent for sex. She has recently begun to develop fully functional hermaphrodite sexual organs. She often shows off her big bulge in her pants.
(1994) Gadget's sex drive has not diminished. In fact, she craves sex, and is a highly skilled lover. Her large belly and breasts are an attractive addition. Her musk and cum are addicting to others. She can grow her sheath, cock, and balls at will.
(1995) Gadget's sexual needs have grown, but so has her libido. She can now cum with minimal stimulation, and can be very submissive or dominant, depending on her mood. She enjoys her large breasts and belly, and her cock has reached massive proportions.
(1996) Gadget's sexual urges are almost too much for her to handle. Her cock is the largest she's ever had, and her balls produce an immense amount of cum. She can also grow additional arms to help satisfy her needs.
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It is now 1997, and you are Gadget's boyfriend. She lives in a nice suburban neighborhood, and your house is right next to hers. You have spent a lot of time in the past year watching over her, and helping her adjust to her new life. You have a key to her house, and let yourself in. "Hey Gadget! It's me, I'm here!"
You see Gadget sitting on the couch. "Oh! Hello! It's good to see you! Sorry I'm not really dressed, I'm just relaxing, trying to keep calm. I've had a bit of a tough day. Come sit next to me and tell me about your day!"
You sit down and tell her all about the workday. When you finish, you ask her how she is doing.
"Well... my cock was very horny all day, and I've had a few orgasms already. I haven't grown any new limbs yet today, but that might change soon."
She rubs her large breasts, and then grabs her belly and shakes it. You can see a wet stain spreading across the crotch of her shorts.
"My hormones are still driving me crazy. It's been getting better, though. I can at least concentrate enough to go to the lab, but the moment I'm back home, I'm usually horny as hell."
She grabs your hand, and puts it on her bulge. Her shorts are soaking wet, and her cock is very hard. "Would you mind taking care of this?"
She gets up and pulls her shorts down. She grabs her thick sheath and cock, and holds them out to you. Her powerful pheromones pump into the air. You feel your cock grow rock hard, and your body relaxes. You lean forward, and kiss the tip of her cock.
She moans as your tongue slides across her head, and her precum begins to flow. She puts her hands on your shoulders and thrusts into your mouth. You begin to suck her cock, tasting her salty fluids. She starts to pant as she thrusts into your throat, and her cockhead bumps against the back of your throat.
She reaches around your head and pulls you closer, shoving her cock into your throat. You feel her precum flow into your mouth, and your throat tighten around her cock. She moans as she thrusts faster, pushing her cock into your throat with every stroke. You feel her balls tighten, and she screams as she cums, filling your throat with her warm cum.
She lets go of your head, and pulls her cock out of your mouth. You feel her hot seed trickle down your throat, and your own cock twitches. She leans down and kisses you, tasting herself on your lips.
"Thanks for that! Now I can go about the rest of my day in peace!"
You look down and see her cock is still hard, and your own is straining at the front of your pants.
"Gadget, do you think I could... get some attention too?"
"Of course! That was the plan from the start!"
You stand up and unbutton your pants, and pull them down. You step out of your pants, and Gadget grabs your shirt and pulls it over your head. She pulls you down onto the couch, and lays on top of you, her cock pressing against your stomach. Her huge gut smothers your stomach and lap. She grabs your cock and gives it a few strokes, and your body shudders.
"Please! Don't stop!"
She grins and leans down, kissing you deeply. Her tongue pushes past your lips, and slides against yours. You feel her heavy balls weigh fatly atop your thighs. She continues to stroke your cock, and your body begins to shake.
"G-gadget! I-I'm about to..."
You can't finish the sentence. She squeezes your cock tightly, and your vision goes white as you cum, spraying cum over her stomach.
She giggles, and licks the cum off her hand. "Mmm! Thanks for the snack!"
She rolls over and sits up. She grabs her own cock and begins to stroke it. "Now, for the main course..."
She grabs your legs and pulls them apart. She rubs her cockhead against your asshole, and you gasp as her precum trickles into you. She slowly pushes her cock into your ass, stretching you open. She slides her cock in and out of you, her massive girth opening you up. You feel her thick sheath pushing against your asshole, and her huge balls swinging against your ass.
You feel her cock throb inside you, and her warm cum floods your ass. She cums for a full minute, before pulling her cock out and letting her cum trickle out of your ass.
"Oops! Looks like we made a mess. Maybe we should go take a shower and clean up."
"Yeah, maybe we should."
You get up and follow her into the bathroom. You turn on the shower and step into the hot water. She steps in with you, and you feel her thick sheath rub against your back. It is covered in thick, silky mouse fur. You feel her massive breasts push against you, and her hard cock presses against your back. You feel her cock throb and grow, and she moans as her cock swells, and her cum starts to flow.
She cums all over your back, and her thick cum runs down your back and over your ass. She moans and her cock continues to pulse, spraying her cum onto your back and ass. There is more than ever before, and you soon realize why: a second pair of balls has dropped into her sac. She has four huge testicles now!
You feel her cock push against your asshole, and her thick sheath rub against your back. She pushes her cock into your ass, and you feel her huge cock fill you. She slowly begins to thrust, her massive girth stretching you open. You moan and press your ass against her, and she grabs your shoulders and pushes you against the wall. Her huge breasts squish against your back, and her cock throbs in your ass. You feel her second pair of arms reach around to grab your cock and jerk you off while she fucks you.
She cums, spraying her cum deep into your ass. You feel her thick cock throb inside you, and you moan as you cum all over the shower wall. She pulls her cock out of you, and turns you around. You feel her cum flow out of your ass, and trickle down your thighs.
"Sorry about the mess. I couldn't hold it in any longer. My new balls are fuller than usual, and they produce way more cum."
"Yeah, I noticed! Four huge balls and a bigger cock? Wow!"
"Oh, the fun doesn't stop there. Look!"
She spreads her legs, and her cock drops between them, a third pair of balls hanging heavily behind the first two. Her sheath is longer and thicker, and her cock is much longer and thicker than before. Her head is a bright red, and her sheath is dark purple, covered in thick veins. Her balls hang heavily, and you can see a fourth pair of balls starting to swell.
"Wow, a fourth set of balls?"
"And they're still growing! I can't wait until my fifth set drops, that's when I'll be done. And then I'll be ready for the big day!"
"The big day?"
"Yes, the day I'll breed my first male. I'll give you a huge, fat belly and lots of cum."
"I can't wait!"
"Good. Now, let's finish cleaning up. We're both covered in cum."
"I don't mind a bit."
"I know you don't. Now, let's get you cleaned up."