I know you're out there!

It did not take 18-year old Samuel long to get used to his new mature female body.

He did not feel ashamed when he looked at it in the mirror.

He did not feel guilty when he played with it in the shower.

He did not feel guilty teasing his sister who was now a very horny teenage boy and was watching her through the crap in the door.

He found it quite a turn-on knowing she was watching him.

Usually he would leave it there but today there was something playful and mischievous inside of him so he shouted I know you are there Rebecca.

Why don't you come in and let me see what I can do to that hard-on for you?

Rebecca knew it was wrong to spy on her brother.

She knew it was wrong to find him attractive.

She knew it was wrong to masturbate whilst watching him taking a shower.

But she could not stop herself.

She had no idea he knew she was watching him slowly drying himself off.

She had no idea that he knew she was pleasuring herself outside the bathroom until he shouted for her.

She knew deep down they were still brother and sister technically related to each other.

She knew she had to be strong and resist her male sexual urges.

She knew she should be strong and not walk into the bathroom.

By the time that thought enter the brain it was already too late.

She was in the bathroom and her brother was down on his knees in front of her sucking away on her big hard cock.