Because he didnt appreciate me, always put me down, treated me as an option and also cheated on me before that. I was feeling like crap and utterly defeated when another guy came along and was being super nice and saying all the things i wished my bf had said to me, so i though 'fuck this, life is only short, im doing what I want'. Seeing as he would constantly accuse me of it anyway, constantly tell me i was a shit girlfriend after i would bend over backwards to try and keep him happy even doing things i wasnt comfortable with really just to jeep him happy and get him off my case. NOTHING ever worked, NOTHING was good enough, last argument he completely ignored me for a week til i mentioned this other guy and now suddenly he is heartbroken and cannot beleive i have treated him this way along with everything else apparently. The amount of nice things i have done and said just gets forgotton about and now im the worst gf ever AND i also cheated on him after everything. The guy just seems to WANT to be a victim its so weird.