--Disclaimer-- 
The characters and events in this story are entirely fictional and are not designed to represent real life situations or relationships.

Chapter 1: One Small Step

"Ok kids, we'll be back around 8. Dinner is in the fridge. Behave."
"Ok, Mom."
The door slammed closed and the two of them looked at the other and nodded in excitement. This was the first time they had been left alone without a babysitter. 10 year old Jake and his 15 year old brother Dexter had the house to themselves for the next 6 hours while their parents were out at a wedding. The two bumped fists then went to their own rooms.

The young chimps were always inseparable when they were younger, but when Dexter hit high school he became a little more distant. Though Jake certainly noticed, he didn’t bother bringing it up. He too was growing up and they were developing other interests. 

What Jake didn't know however, was that one of Dexter's interests he discovered when he turned 12 was other boys. Once he began changing clothes in gym class, he found himself peeking over to see his friends in their underwear. Ever since then the older boy went out of his way to catch glimpses of not just his locker room classmates, but any boy he could find. At the local pool, changing rooms in the mall, wherever the opportunity presented itself really. With his teenage hormones raging, he couldn't help but get aroused pretty much all the time. Everyday after school from age 13 onward he has quickly ran up to his room to rub out the frustration before his little brother came home. However, it was now July, and finding the alone time he needed was usually limited to his shower. The chimp's dick was quite impressive for his age. A solid 6 inches when erect and about 4 when flaccid. His balls were growing quite heavily as well,  hanging down off of him a good bit. 

Jake on the other hand was just barely starting puberty. A few months earlier his balls had dropped and now hung ever so slightly below his dick. He was still relatively small when flaccid, but he was experiencing frequent erections which caused his little member to swell up to 4 inches. 

The two of them used to shower together a lot, but that all stopped when Dexter started checking out other boys. He was afraid what might happen if his little brother saw him sporting a massive hard on. As Dexter sat in his room playing games, he heard the sound of the shower down the hall rush on. He perked up, pausing his game and looking down the hall. Jake's bedroom was directly across from the bathroom and he would occasionally walk back and forth before his shower between the rooms. Nothing out of the ordinary of course, but Dexter also knew Jake had a habit of wearing a bit less when their parents were out of the house. Although he never really thought about checking out his brother before, a feeling came over him that he couldn't ignore. As he watched the hall, suddenly his little brother walked across between the two rooms. He was completely naked. Dexter's eyes widened as for a brief second he caught a glimpse of Jake's dick flopping around. Immediately Dexter's own dick twitched into a semi. Looking down at his pants his hand reached to the fly and he felt himself getting hard. 

"Shit," he mumbled and stood up to go close the door. He pushed it closed and then turned around pressing his back to the door. Looking down at himself he was now completely hard and his pants had gotten tight trying to contain his boyhood. He sighed and unbuttoned his pants. Pulling down the zipper to lose the tension, he quickly let them fall to the floor. 
"This is bad," he thought. "I don't want him too, do I?" As he thought about Jake being naked just down the hall, his teenage dick twitched. 
"Ah man," he whispered. "I think I do. I…I wanna see his thing." He reached into his tented boxers and gently stroked himself. "I bet he's a lot bigger than he used to be." Slumping downward, his dick poked out of the opening of his underwear and he sat on the floor. He couldn't help but start pumping his fist up and down as he thought back to the few seconds of Jake walking between rooms. 

Just as he felt himself staring to breathe more heavily the water shut off and the echoes of the shower fell silent. Immediately he released his dick and tucked it into his boxers. He got on his knees and slowly popped the door loose, opening it just enough to have a view of the bathroom’s doorway and the hall. As he waited to see if his little brother would exit the same way he entered. His heart pounded heavily in his chest in anticipation. Finally after what seemed like an eternity, the bathroom door swung open and out he stepped. 
There he was in all his pure and innocent glory! Dexter stared through the open crack in his door as Jake stood in the doorway completely bare from head to toe. The boy rubbed his head with a towel hiding his face from seeing down the hall to Dexter's room. Dexter's eyes widened and fixated on Jake's dick. HE WAS HARD! He couldn't believe what he was seeing. His 10 year old brother's little member stood proudly out from his body. It was WAY bigger than Dexter remembered from when they used to shower together. 
As Jake moved the towel away from his face, Dexter snapped back around behind the door and slammed it shut. The sudden rattle caught Jake's attention and the naked chimp walked across the hall floor and knocked on the door. 

"Big bro? You ok?"

Was he caught? Dexter didn't know what to do. He just kept himself propped up against the door. His thoughts racing.
"Oh God, did he see me? Shit I'm such an idiot. He's your brother. But…but…that cock though! I mean damn, he's as long as I am while soft. I wasn't anywhere near that big when I was his age. Crap, now I want to see it closer."

"Dex, you there?" He asked again. "I was gonna grab dinner if you wanted me to heat yours up too."
Dexter suddenly snapped to, and stood up. He gathered a pair of clean boxers and a t-shirt from his drawer, then cracked open the door. 
"Oh hey you're done," he said, poking his head out of the door, and showing his clothes. He looked down at Jake, trying to maintain his cool. Luckily thanks to the downward perspective, Jake’s head covered the view of his little member.  "Yeah, that sounds good. I'm gonna go get cleaned up."

"Ok," Jake replied smiling. He then turned around and walked back to his room. 

The boy didn't seem to even think to cover up. He left the towel draped over his shoulder as he walked back to his room. Dexter watched nearly drooling on the floor, admiring the younger chimp's butt as it wiggled away from view. When Jake's door closed Dexter leapt into the bathroom as fast as he could. Stripping off his remaining clothes, he stood in front of the mirror and looked down at his throbbing erection. 

"Holy shit," he muttered. "What's wrong with you, Dexter? He's your little brother. Oh man, but still…" he reached down and began stroking himself again. "Damn, I want to touch him now. I want him to touch me. Oh man." He released his dick and rolled his fingers across the tip catching the leaking precum. He brought it up to his lips and licked it. 
"I wonder what he tastes like?" He shook his head from side to side and leaned over to the shower turning the water on. "Just gotta cool off," he thought. "Yeah, cool off and eat. That will clear my head."

… …

While the shower was good for him. It calmed his nerves and relaxed him considerably. After dinner he and Jake decided on streaming a movie. They decided on a favorite that both of them loved. Primates of the Caribbean. 

It was just past 6, and the movie started. They sat side by side on the couch, both wearing loose fitting gym shorts over their underwear. With it being so hot, both opted to leave their shirts off. Normally their parents would prefer they keep them on while it was still light out, but since they were alone for the evening it was a nice reprieve from the rules. A bowl of popcorn sat between them which the two munched on periodically. 

About halfway through the movie Dexter's phone beeped from a text notification. It was upstairs in his room, but was loud enough to echo down the stairs. Dexter got up and headed for his room. 
"Need anything while I'm up?"
"Nah, I'm good." Jake replied, eyes fixed on the movie. 
Dexter smiled, and headed upstairs. Reaching his room he grabbed his phone to see a message from their parents. 

Hey sweetie. Big traffic jam on our way back, looks like we'll be a lot later than 8. Get yourselves to bed on time please. Love, Mom. 

"Sweet," Dexter said to himself. Putting his phone down he stepped out of his room. 

As he passed by Jake's room heading for the steps he noticed something unusual laying on his little brother's bed. Carefully, he quieted his footsteps and peaked into the room. Walking up next to his bed his jaw dropped as his suspicions were confirmed. It was a pair of his own underwear. Not only that, but the same pair he had just taken off before his shower. He remembered tossing them in the bathroom hamper as well. Did…did Jake steal them from the hamper? Why would he…? 

"Hey, it's almost at the best part!" Jake shouted up the stairs. Dexter jumped, leaving his boxers on Jake's bed, then ran back downstairs. He sat back down beside him, and bent up one leg on the couch. Jake hit play on the remote and the movie resumed. 

Dexter was a bit too distracted to pay attention to it now though. His little brother had a pair of his used underwear. He couldn't quite figure it out. "Was he trying them on? After all, he still wears briefs. Or was it for a prank?" His thoughts continued. "Or..wait…no he couldn't be like that at his age…could he?" He glanced over to him. His eyes looked down from the young chimp's face to his chest. He was still undeveloped there. Looking further down his eyes stopped on the boy's shorts. They were an old pair of his own that he had grown out of. 
"He looks really cute in them," he thought to himself." As he observed his little brother, he noticed that he would occasionally scratch at his waistband. Dexter smiled realizing that this one small moment might lead to something more interesting. He took a deep breath and decided to see where one simple question might lead.

"Are those itchy? I know they're still a little big for you."

"Huh? Oh." Jake looked down as he was involuntarily scratching his hip. "No, the shorts are fine. I think mom might need to get me some bigger undies though."

"Ah, well you're growing up rather fast," Dexter replied, rubbing the top of his head. "If you want you can try a pair of mine sometime."

Jake's face lit up. "Whoa you mean it? Yours are so cool!"

"Yeah no problem. Besides, you'll want some before you start school in the fall. Most guys have 'em on for gym class."

"Thanks Dex, you're the best," he replied. He readjusted his shorts, then scooted against Dexter's side. The younger chimp yawned and snuggled closer.
Dexter could tell that it would be now or never if he wanted to see just how comfortable he could be with him. 
"Pretty hot in here huh?" Dexter said reaching down to his own waistband. "Mom texted me, said they were gonna be late. I think we can afford to be a little cooler tonight." He then lifted his hips which got Jake's attention. The boy sat up and watched as his older brother pulled off his shorts. "Ah, there we go." He lifted his arm up and Jake returned to snuggling under his arm. "You can take yours off too if you want."

O…Ok." Jake quickly pulled off his shorts and tossed them on the floor. 
The two chimp brothers were now snuggling in their underwear on the family couch. Dexter could barely keep himself from getting hard, feeling the warmth of another boy against him. "So what if he's your brother," Dexter thought to himself. "It feels so good to be able to enjoy time with a boy like this and not be made fun of."

As Jake reached over for a few pieces of popcorn, he suddenly jolted his hand back. He shifted his hips to one side and bent his leg up covering his groin area. Dexter glanced away from the TV to see just what Jake was doing. Smiling he watched the little chimp wiggle himself around trying to hide the fact that he had gotten hard while snuggling with his brother. Again, Dexter decided to take another chance. 

"You don't have to hide it, you know." Dexter said, lowering his leg to the floor revealing his tented boxers to his little brother. "Happens to me all the time too." Jake turned his head around and then froze as he made eye contact with his older brother's tent. His own little member twitched the second he saw it, and he fixated on Dexter's boxers.
"Relax little bro," Dexter replied, as he let his arm move from the boy's side to his upper groin. "It's not like we didn't use to see each other in the shower every night, right."

Jake shook his head and snapped out of his trance. He swiveled around until he was laying on his back. His head draped over Dexter's thigh. "Oh yeah, I almost forgot about that. Why did we stop?"

"Uh," the older chimp scratched the back of his head. "Well you were too young to understand all the changes boys go through. I didn’t want to scare you or anything."

Jake looked to the side watching Dexter's tented boxers twitch. He then looked at his own briefs which did the same. It was then that he understood what Dexter meant. 
"Oh, right," he mumbled, sounding disappointed. "Wait!" He suddenly then sat up and turned around facing Dexter. "But I'm older now and we both get hard, so we should start doing it again."

"Uh," Dexter said. He was eager to say yes given Jake's enthusiasm. Especially because it would let him see the boy's body unobstructed, but he was still hesitant. "Mom and Dad probably wouldn't let us though." 

"Awe man," he slipped back down, and looked at the movie. "I really wanted to see you naked big bro."

Wait. WHAT!? Did he just hear that come out of his little brother's mouth? The innocent kid that he grew up with now wanted to see him naked. 
"You do?"

"Heck yeah!" Jake turned again to face Dexter. His hands clenched into fists out of pure excitement. "I bet your dick is all big and cool now."

"Holy shit, where did this all come from!" Dexter thought. He was stunned. Since when did his little brother take such an interest in his body. "Do…do you really wanna see it?" Dexter said, scooting to the edge of the couch. Well this was an unexpected turn of events. He thought that he might have been pushing his luck too far by showing off his tented boxers, but it seems Jake was just waiting for an opportunity to ask. Dexter stood up and placed his thumbs under his waistband.
"I'll show you mine if you show me yours."

The excited younger chimp leapt from the couch and immediately pulled his briefs to the floor.
…It finally happened! Dexter now was looking up and down at his little brother's naked form. He was beautiful. The most perfect boy he had ever seen, and he was right in front of him with a gloriously hard little cock. Dexter licked his lips and pulled down his boxers. His 6 inch chimp cock sprung out and pointed straight at his little brother. The young chimp giggled as he looked at his older brother's maturing cock. 

"Wow, you're so big!" He exclaimed, stepping forward to get a closer look. "I bet you can cum and everything!"

"How…how do you know about that already?" Dexter stuttered.

"Oh please, I'm 10. I’m not stupid.

The evening had taken a strange and drastic turn for sure. Dexter at first thought he’d be the one slowly introducing his innocent younger brother to things like masterbating and sex, but it he seemed to already know more than was expected. Just 30 minutes earlier Dexter expected himself to maybe go as far as "accidentally" touching his little brother's bulge. Now however, Jake seemed to be the one with more knowledge than he did, and was almost taking charge of the situation. This flustered the older chimp, but still aroused him considerably. He was about to tell his younger brother it was ok to touch, when the chimp took the initiative himself and reached out with both hands grasping his cock. Dexter gasped as he felt his little brother’s hands wrap around his sensitive member. The boy was elated as he rubbed his fingers all over the hairy teenager’s length. Tilting his head back and closing his eyes, he let the young chimp rub him to his heart’s content. Dexter’s breath became heavy as he moaned while being messaged by his curious brother’s hands. 

“Man, feels like you’ve needed this big bro.” Jake said, continuing to stroke Dexter’s cock. He looked up into his brother’s eyes and smiled. “I’m not moving too fast for you am I?”

“I…uh…” Dexter was pretty much frozen between being too horny and too stunned to think. His innocent 10 year old brother was completely naked and giving him his first ever handjob in their living room. “Uh…aaaaah. Yeah!” He resigned his worried mindset to his lustful teenage desires and just let Jake pleasure him. “Oh yeah, Jakey. I love you so much.” 

The boy giggled and continued working his hands up and down over Dexter’s cock. He pushed and pulled the teens’ foreskin across the head, working his little fingers across every inch of the older boy’s member. Jake's own dick twitched as he enjoyed making his older brother feel good. 
Despite his age he was already rather experienced when it came to sex. He and a few of his friends had already discovered the pleasures of stimulating themselves. Often they would end up giving blowjobs to each other. Ever since then, Jake had actually really wanted to try fooling around with his brother, but didn't quite know how to go about it. Luckily for him, Dexter's interests overlapped with his own. 

"How am I doing?" Jake asked, looking up at Dexter's face. 

"Shit Jake, where did you learn to do this?"

Jake didn't respond. He just smiled and licked his lips as he looked at Dexter's cock. It was now starting to leak precum, which from Jake's perspective looked extremely inviting. Closing his eyes he leaned in and licked the tip of it. A spike of electrifying pleasure shot through Dexter's whole body. His knees wobbled as he felt his little brother's tongue lap up his precum. 

After that Dexter's animal instincts switched on in his brain. He stepped back out of his brother's reach and bent down scooping the boy up into his arms. 
"Wha?" Jake shouted as he was lifted in the air. "What's going on?"

"We're going upstairs, that's what," Dexter said as he pressed the TV's power button with his toe. Dexter's fantasy was coming to life, and he was ready for an unforgettable night with his little brother.