First time you gotta take it easy on her, anything after that and the real freak comes out in me.
The first time you have to let them think it was good but yet somewhat tame, then when you start going crazy on her ass and pulling some hardcore porn maneuvers she will have to rethink whatever it was she thought of you hehe.....
If done this a few times and the chicks dunno what to think, funny to make their head spin sometimes....
PS, if its just a booty call then you can just skip everything i just said and go to step 2