She leaves by herself

While mark was desperately trying to come up with a plan, when his sister began to get up off the sofa.

"I'm going to the toilet, here" she said, tossing him the tv remote "you can choose something"

Mark instinctively caught the remote, forgetting that he was still covering the stain on his jeans. He scrambled to cover himself "t-thanks" he mumbled.

Ash didn't seem to notice, although mark though he saw her smirk a little when he lifted his hands. She could possibly know…could she?

Mark waited patiently until he heard her footsteps disappear upstairs and the bathroom door firmly shut. Once he was sure the cost was clear he snuck upstairs.

There were no problems on the way to his room. He carefully opened his door trying to make as little noise as possible as his sister was still just across in the bathroom. However, as he opened the door an moved to step inside his vision shimmered again. Knowing what might happen he rushed into his room and quickly shut the door behind him. He hadn't made it two steps before everything shimmered again and this time he felt himself get hard. He knew what was happening.

Mark began stripping off as he made his way towards his bed. He had managed to pull off his socks and shirt before his vision flickered again. By the time he reached his bed his cock was straining in his pants. He undid his belt and pulled his jeans down carefully past his boner before removing his cum filled boxers, leaving him totally naked.

By now mark was **** for release. He wrapped his hand round his hard on and began stroking himself. As he pleasured himself he thought back to earlier, to his sister's perfect body, The curves of her luscious breasts, her unshaven mound and her amazing butt. Part of him wanted to stop time again, find her and fuck her senseless but he knew he couldn't risk it. Besides he doubted he could last that long.

Mark felt himself getting closer to his climax and soft involuntary moans and groans escaped his lips. "Oh, ash" he moaned as he imagined slipping in between her legs and fucking her.

As he moaned her name, he opened his eyes and imagined her standing there in the room with him, totally naked. It was only there for a second, but it was like she was really there, butt naked, her clothes scattered around her as she walked straight towards him, a look of pure lust on her face.

He began stroking faster, **** to cum. It was long before he pictured her again. She was much closer this time, she was practically standing over him, watching him jerk himself. It lasted longer this time. He imagined her still naked with the same slutty look on her face. He lay back as he imagined her place her bare legs either side of his. Mark lay flat on his bed stroking his cock as his imaginary sister straddle him like a stallion. He look up and imagined her playing with her tits and smiling. He had never seen his real sister smile so beautifully.

Mark couldn't take it anymore. He needed to cum. He tried to line up his cock with the hallucination's pussy. He didn't care at this point if it was real or not but as he arched his back and tried to push into her, she vanished. At the same he was overcome with pleasure as he climaxed. He moaned loudly as His cock erupted spilling his hot seed all over himself. He tried to stay quite as his orgasm seemed to last for hours. He didn't want his sister to catch him like this.

Eventually his climax subsided as the last of his cum dripped onto his stomach. As he lay silently on his bed recovering for his intense experience he was certain he heard noises from his wardrobe. Once he'd recovered enough he quickly check but everything seemed fine.

He quickly looked at himself in the mirror and saw that his lower body was drenched in his own cum. So much for cleaning himself up.