This guy I've been seeing (not dating) for close to a year told me one time during sex to stop scratching his back, when I asked why he said it hurt. I automatically thought it was because he didn't want other girls to see since he's supposedly such a tough guy... So why would some scratches hurt right? Today we saw a show where a guy was hurt and he mentioned that he thought that wouldn't hurt so I brought up "that wouldn't hurt but scratches during sex does?" he very sarcastically said "no I said that so my 11 other girlfriends don't see it" and rolled his eyes... I don't think he was being sarcastic.
Almost everyone I know of acts like they love being scratched.