Hot Summer Job/Sit and calm yourself down so your nerves don't give you away
You toss the throw blanket in your laundry basket and then immediately collapse onto your bed and breath out a very large breath you didn't even realize you were holding. Holy crap! What did you just do!? And seriously, you have Bree agreeing, no, excited to do it again? Your mind begins to fill with the thought of having sex with your little sister tomorrow around the same time, how good it will feel to have your dick wrapped in her tiny body.
It is strange, you are looking forward to it as though you didn't just get done doing the exact thing you are thinking about. In fact, your cock is even beginning to inflate in anticipation of taking the kid's vagina for another spin. You think back over what you know about her sexual knowledge. She seems to know about the mechanics of the act of sex, but you couldn't really tell how much she knew beyond that. Well, she didn't seem to know that penetrating the vagina with your penis was actually CALLED sex, so it would make sense if her knowledge was lacking in other areas. You still find the thought particularly appealing that she seemed to think that your cum came from her and not you.