By the way, if anyone knows what body parts levels do, I'd appreciate it. (Didn't think anyone would actually reply to such an old thread.)
I believe it was supposed to either make her Lust or to get her to climax faster, and I will say to lvl up her body parts to max takes forever, but if you want to you can lock in an animation and it will continue to lvl up the selected parts for whatever sex position your in. For me I love the thought, its very erotic but there isn't anything that effects it on a gameplay mechanic sadly.
