I was in a violent relationship, on the reciving end of quite a few punches, I also had to stop her beating her kids up, it wasnt pleasant atall, no way would I hit back as thats not in my nature, I used to get clawed kicked or headbutted when it was at its worse (PMT time), once had to stop her beating her son with a kettle and shielded him and took the blow myself, I dont know why I put up with so much, I guess you do sadly when you love someone, I'd never put up with that again and would walk out the door the first sign of trouble, they beg forgiveness but just repeat it again and again.
All her other relationships consisted of men battering her, I guess its all she ever knew but still does not excuse anything, if anyones in a relationship like that now, take my advice, get out and find someone better.