My cousin's back and arms look like he's been to war - and this after three months with a gouger. He says he doesn't like the scars, but he likes it when she gets all worked up during sex and the expression of pleasure it represents. He jokes that afterplay now consists of her playing nurse with Antiseptic.
Personally I've had to hold one girl by the wrists behind her head, because she couldn't keep herself from digging into my back. I was tired of bleeding.