Every summer the Smyth family drove out to the forest and spent a month at the family trailer. It was nothing fancy, a queen size bed for Mom and Dad and a pull out couch for the kids Chris and Cecilia. Chris and Cecilia had out grown the couch years ago though and now shared a tent with a king size air mattress that was set up beside the trailer. The tent always got set up right outside the bedroom window of the trailer so the parents could yell at their rowdy children without getting out of bed. While at 19 and 21 Chris and Cecilia were no longer children the tent still got put on the same patch of dirt it always did.
Like many families while camping the Smyth's cooked over a fire pit and shared ghost stories over s'mores. Eventually the flames turned into coals and the coal began to burn out. Someone suggested it was bedtime so they put out the rest of the fire and retired to their various sleeping quarters.
Instead of sleeping bags Chris and Cecilia had put a sheet on the air mattress and had each brought their own blankets to use. They found it much more comfortable than being trapped inside a sleeping bag. Every night they would take turns changing and then fall asleep facing away from each other on opposite sides of the air mattress.
Soon, Cecilia was asleep but there was a weird noise keeping Chris up. He couldn't quite tell what it was at first. It was a sort of metallic creaking with moaning, mumbling noises. As he listened the noises grew louder and he knew what he was hearing. It was the rhythmic creaking of the trailer rocking while his parents had sex not 5 feet from where he was trying to sleep. He could hear his mother's moans as his father plowed away.
He knew it was wrong to listen and he should be grossed out but he wasn't. Instead he was aroused and soon his cock began to harden. As the rocking next door became more urgent and his mother's moans became louder all Chris wanted to do was stroke one out and climax when his mom did. He tried to be careful as he pulled his dick out of his pajama bottoms. He know any movement he made risked waking his sister. Soon he was slowly stroking his firm 7.5" penis. He quickly forgot himself though and began rubbing himself quickly shaking the air mattress. He heard his sister groaned and mumbled something having been jostled awake. Chris stopped and waited for his sister to resume sleeping so he could finish what he'd started. He heard his mother climax and was sad he had missed his moment but that wasn't going to stop him from cumming once it was safe. Unfortunately for Chris fatigue took over and he fell asleep, dick still out, while he waited for a safe chance to finish.
The temperature that night dropped down to 10C and Chris and Cecilia slowly moved towards each other in their sleep to keep warm. Eventually, they were spooning which was how Cecilia found herself when she woke her in the middle of the night.
Having been woken Cecilia noticed a couple of things. First was that she had to pee. Not badly though so she decided to try and hold it till morning, after it had started to warm up. Second was that not only was her younger brother spooning her he was sporting an impressive erection. She couldn't tell exactly how large it was but she could feel its firm length pressed against her ass. It gave her an idea.
See, while Chris had thought she had been sleeping Cecilia was also kept up by the sounds of their parents carnal actions. She had tried to ignore both them and the growing dampness between her legs. She had just begun to fall asleep when her perv of a brother began jerking off behind her. Jostling her fully awake again while she listened to her father bring her mother to completion.
She'd fallen asleep thinking about it and was sure her brother had to. Given her sleepy, horny brain Cecilia decided to have some fun with the young prick behind her. She slipped her bottoms off and pressed her ass firmly against her brothers cock and began grinding slowly. While she was grinding against her brothers cock she started rubbing her clit. She moaned softly enjoying herself immensely. Then she got her wish and felt her brothers hand firmly on her hip.
"What are you doing?!" he whispered.
"Giving you what you want you little perv," she said. "I know you were jerking off listening to Mom and Dad."
"Who's the perv now? Where did your pants go?" he sounded scared but had started thrusting back against Cecilia's firm ass. Her skin felt so warm and smooth and his cock had fully taken over at this point. He knew what they were doing was wrong but all he wanted was more.
Testing the waters he began running his hands all over her body. He caressed her curves and ran his fingers up and down her legs. She moaned in response encouraging him to keep going. He reached for her breasts and began playing with her nipples. He could feel precum dripping down his cock.
The whole tent smelt of sex and it spurred Chris on. He reached between his sister's legs and began rubbing her clit. It was more than Cecilia could take. She tended and arches back against him as her first orgasm washed over her.
"I need to be I side you" Chris begged.
Cecilia didn't say a word but opened her legs and reached for his cock to guide it inside her. Pure bliss ran through both of them as Chris's thick dick slid into Cecilia's tight pussy. He started thrusting himself deeper holding onto her hips to pull himself in. Each stroke pressed against her g-spot and he swiftly brought her to orgasm a second time. He could feel her hot cunt squeezing his dick over and over again as she road out her orgasm. Chris almost finished right then and there but held on. He couldn't risk filling her pussy with spunk.
Once Cecilia relaxed again Chris pulled his dick out and pressed it against her asshole but she stopped him. The pressure in her bladder was growing and she wasn't sure she could hold her piss much longer.
"Before you fuck me in the ass you have to do something for me." Cecilia said.
"What?" Chris said frantically not wanting to stop.
"Open your mouth and shut your eyes." came the response.
Christ felt hesitant but couldn't ignore his need to cum so he did what she wanted. He could feel Cecilia moving around the mattress and then felt her straddle his face. Her cunt smelt amazing, sweet and a little musky. He sat up a little and began tasting her pussy. Cecilia moaned in response. She hasn't expected her brother to start eating her out but she wasn't going to stop him now.
Chris expertly navigated his sister's pussy. He licked up and down and sucked on her clit. He could feel her dripping onto his chin. He began probing her depths with his tongue. Cecilia swore as she came again with her brother's face buried in her snatch.
"Stop." she hissed. "Open your mouth again."
He did and held it open just below her.
"If you want to fuck me in the ass you're going to let me piss in your mouth and you're going to drink every last drop."
Chris didn't even hesitate. He pressed his open mouth against her cunt and covered her piss hole. Cecilia relaxed and felt a wave of relief as she began to pee. It was just a little at first, peeing somewhere she wasn't used to was trickier than she expected. She heard Chris swallow and felt his tongue against her, searching for more. She gave a firm push and piss shot out of her. She had had a lot to drink before bed and it was all coming out now. Chris struggled to keep up but kept swallowing gush after gush of Cecilia's per. Some trickled out of the side of his mouth despite his best efforts.
After what felt like forever Cecilia was finally done. She felt relieved and relaxed. There was a slight pause while Chris finished swallowing and then he began attacking her pussy with his tongue again. First, he used a few broad strokes to wipe her clean and then he focused on her clit, circling it over and over till she was once again spasming with pleasure.
When she was done cumming she fell forward onto all fours over top of Chris. In her new position he could see her asshole. He licked it a couple of times and then began shimmying out from between her legs until he was behind her. Once again he pressed his dick against her puckered asshole. This time it slide in easily. He started slowly while she adjusted to his length.
Soon they had found a good rhythm. Chris leaned forward and played with Cecilia's breast and nipples while he slowly thrust in and out and deep as he could. He was having to much fun and didn't want to finish to quickly.
Cecilia had other plans. She had been furiously rubbing her clit while her brother fucked her up the ass. She could feel her muscles tensing as a warm glow flowed through her body.
"I want you to cum in my ass" Cecilia said trying not to wake her parents. "I'm about to cum again and I want you to fill my ass". Chris didn't need any more prompting. He had been on the edge for a while and his sister's words were more than enough to push him over. He began fucking her hard and fast. He felt her ass tighten as Cecilia began to orgasm so he pulled most of the way out and then plunged as deep into her hot, little ass as he could. They came together as Chris pumped shot after shot deep into his sister's ass while her orgasm milked every last drop out of him.
Exhausted, they both slumped against there pillows still locked together. As they drifted to sleep, Chris's arms wrapped around his sister he said "Tomorrow night let's go skinny dip and fuck on the beach where we can't be heard." Cecilia just nodded in agreement as she fell asleep.