So recently my ex girlfriend (who is now my best friend) started question why i still like her and when i give a reason she just says "but i'm a psychotic bitch" and i really don't like hearing her say that. However there is some element of truth to her words. She has a horrible sadistic streak; when we were dating she would pinch me, pull my hair and sometimes but not very often choke me, now the only ones i kick a stink up about was the hair pulling and pinching as they brought on a sharp pain that couldn't be ingnored for long, as for the choking if it got out of hand i would dig my nails into her wrist if this didn't work i would choke her back but she classifed that as playing. Now with all that said i still like her and wouldn't mind getting back to together if i got the chance because she really is a nice person and has supported me in coming out as trans, i should also mention that none of what she did hurt all that much and those that did were easy to stamp out. I am simply wondering if anyone has been through something similar or has some form of input on this situation
There are times when you have someone characterize herself as something negative that you probably ought to take her seriously. This is further reinforced by your descriptions of physical harm. I would characterize these behaviours as both wrong and dangerous (choking, for example). Keep her as a friend, if you must, but I would counsel not pursuing anything more. It is estimated that about 10% of people out there are borderline psychotic (includes people in business, professions, etc.), characterized mostly by an absence of empathy. It would be wiser to steer clear of such people.
I have to agree with greatwhale on everything said. I can't fathom a justification where pinching, pulling hair and choking someone is acceptable behaviour.. even playfully. The way you describe it sounds unhealthy. As callous as it sounds, involvement with somebody of that nature sounds like a downhill journey which should be avoided.