I've seen some 'nerdy' girls into all kinds of crazy sh!t. They are the ones that will surprise you in the end! I knew a sunday school teacher once that got off on the dubble stuff. Although, I've only done that once, it was hot to know she was totaly getting off on what see viewed as being a closet slut...

Btw, threesomes don't make you a slut ladies. It only makes you adventerous, which can be a VERY good thing.