cuz really the guy has low esteem and to make them feel better they put the female down by calling her a slut,whore, easy etc. If you ( the female) break up with him than he is thinking " oh she found another guy. She is such a whore" They think that if you found another guy it automatically makes you a whore.
Ouch! Yeah, that would do it! LOL!. Talk about building up someone's self-esteem.............. ~namaste~
but what if his penis isnt small? In fact, what if its like 12 inches long.... he's gonna know thats not true