Mike dropped his stuff at the door and walked into the family room. Happy to be home from a long day at school, he plopped down to watch TV. His senior year was dragging on. He had already turned 18 and was anxiously awaiting college, so he could be free from his parent's control and rules.
He went to he fridge and on the door was a note from his parents.
"Went to the lake, be back on Sunday. Money on the table for food, share with Nicole!"
Damn! His sister was going to be around. Oh well, he'd be fine if she would just stay out of his way. Nicole was Mike's twin sister. Lately Mike hated hanging out with her. He felt weird about being alone with his sister because in the last 6 months she had developed into quite a piece of ass. He didn't feel comfortable about looking at his sister that way, but she was hot, and at 18, he was definitely horny. He had even jacked off to the thought of fucking his sister. But he had to control himself, because that was incest and it was wrong.
Just then, he heard some splashing outside in the pool. He went out to the deck and saw Nicole swimming around in the pool. She started getting out of the water and Mike's jaw hit the floor. There she was in her black string bikini. Nicole was amazing! She was about 5'10" with dark brown hair and green eyes. Her legs were golden tanned and muscular. The bikini top barely covered her 36c tits, and he could just make out her large nipples through the material of the suit. She began to dry off and caught him staring. Instead of saying anything she turned around and bent over to dry off her legs. Mike got a great view of her tight ass and almost blew his load right there.
"Hey sis, I'm going to check my email. Don't bother me."
"Sure, bro," was all she said. She grinned as she stared at his crotch.
Mike went to his room and immediately stripped down. He grabbed his cock and started whacking away, his sister's image fresh in his head. He laid down on his bed to get more comfortable and turned on the radio, so Nicole couldn't hear the sounds of his intense masturbating session. With the music on, he didn't hear the knock at the door. He also didn't hear it open.
"Having fun, Mikey?"
"Damn Nicole, don't you knock?!?" Mike grabbed a shirt to put over his crotch. His face was red with embarrassment.
Nicole just stood there, arms on her hips, staring at her brother. "I know you were looking at me out there, Mike. Is that what you were thinking about? Were you whacking off to little old me? Your sister?"
"Of course not, stupid!" It was all he could think to say.
"Too bad...I thought you were interested. And just when I'm in the mood for a solid fucking. Oh well, guess I'll have to take care of it myself."
With that, Nicole let her hand drop to her waist and slide down the front of her swimming suit bottoms. She leaned her head back as she began to play with her pussy.
"What the fuck, Nicole! Jesus, I'm right here!"
"That's what I was counting on...too bad you don't want it though."
