Paul knocked on his sister, Alicia's, door. He could hear her voice as she was probably on the phone with one of her friends.

“Yeah?” she called out.

“Hey, can I come in?” 

“Yeah.”

Paul opened the door and stepped inside. Alicia was stretched out on her bed. She was wearing shorts and a t-shirt. Her iPhone was pressed to her ear.

“What’s going on?” she asked Paul.

“It’s time.”

“What? Right now?” 

“Yeah.”

Alicia sighed. “Mia, I am going to have to call you back. Ok. Bye.” She ended the call and put her phone down on the bed. She gave Paul an annoyed look as she sat up in her bed. “This free-use arrangement is starting to get out of hand. I sucked your cock last night while you were playing your stupid video game.”

“A deal is a deal. It’s not my fault that you lost the bet.” Paul and Alicia had made a bet on which team would win the NBA championship. They both were avid basketball fans that watched as many games as they could during the season. They had even played basketball in high school. Alicia’s team had even won a championship. 

Paul had bet on one team while Alicia betted on the other. If Alicia won, Paul would have to eat her pussy and ass every day for a week. If Paul won, Alicia would have to be his free-use slut for a week. Their bets were always something sexual, ever since they had hooked up a few months after moving in together. The apartment they shared had Paul’s name on the lease, and, when his previous roommate had moved out during the summer, Paul had asked his sister if she wanted to move in and she had said yes.

They had always been close since they were young and had teased each other sexually after Alicia had turned eighteen, a few years ago. It would have been weird for two siblings to be sexually teasing each other, but Alicia and Paul were unlike other siblings. They enjoyed the sexual tension between them.

Both Paul and Alicia were heavily invested in both NBA and college basketball. She knew every player as well as many of their stats. They saw many games at the arena where their local team played. The first time they hooked up was from a bet that they had made. Alicia had won, and it required Paul to buy her dinner for a week. On the last night, when Paul brought Alicia’s food home, she decided to give him a blowjob. It turned into much more than that as they ended up fucking.

“What do you want me to do?” Alicia asked as she crossed her arms. Paul knew that Alicia was only pretending to be annoyed with him. It was day three of their free-use arrangement, and he knew that she enjoyed it. 

“I want you to suck my cock, and, then, I want to fuck you doggy,” Paul said.

“Ok, come over here. Let’s get this going.”

Paul walked over to her. He dropped his pants and his drawers. His cock was already hard and throbbing. Alicia took a hold of it and began to stroke it. She gave Paul a mock annoyed look and then put his cock into her mouth. Her lips moved up and down on him as Paul moaned. He loved Alicia’s blowjobs as she was so good at them. 

“Precummiing already, are we?” Alicia said as she tasted Paul’s sticky precum on her tongue.

She put her mouth back on his cock and sucked him off. Paul put his hand on the back of her head and moved his cock deeper into her mouth. Alicia took it all. One of her hands went to his cock and she jerked it as she blew him.

Paul could feel his orgasm getting close. “Ok, turn around. I want to fuck you.”

Alicia took his cock out of her mouth and turned around on the bed. Paul pulled down her shorts and then her panties. Alicia had a nice ass that Paul liked to see whenever he could. He put his cock against her entrance and pushed inside of her. Her pussy was very wet and took all of him. He grabbed onto her hips and began to fuck her.

With each thrust of his cock into her, Alicia’s ass would clap against him. Paul loved that sound and tried to increase the volume of it as he fucked her. His cock went deeper and deeper inside of her with every thrust. Alicia was moaning as she took his cock. 

Paul moved his hands down to her ass and spread her cheeks. He looked at her nice pink asshole as he fucked her. He hadn’t gotten to fuck her ass, yet, but he had four more days to go with this free-use arrangement and anal was definitely on it. He rubbed his finger against her asshole for a moment. Alicia continued to moan.

When he felt his orgasm getting so dangerously close, Paul grabbed Alicia’s hips and fucked her harder. Her ass slapped against him with every thrust. Paul’s cum spurted out inside of her as his orgasm hit him. His cum shot out in quick steady spurts as his cock twitched. He kept fucking Alicia until he had emptied himself. 

His cock was wet with her juices and his cum when he pulled it out of her. He could see some of his cum oozing out from her pussy. Alicia turned over and sat down. 

“Are you done?” she asked him, sarcastically. Paul could tell that she had enjoyed it as she was breathing hard and smiling. 

Paul laughed. “Yeah, for now.”