Should I stay or leave

Recently my boyfriend’s mother’s boyfriend got drunk and jumped in my boyfriend relationship problems . it went on for literally two hours on and off . the first time he brought it i didn’t say anything due to respect. then he brought up again i didn’t say anything once again. my boyfriend was right there and at first we was defending me but after awhile he continued to let the man jump down my throat . Just a few minutes ago we got into an argue and i grab his face so he could look at me and he hits me in my face . saying his Mother’s boyfriend was right for all that stuff to me. soo i told him i didnt feel like he defended me good enough , now he’s mad and wants to break up . i honestly was expressing how i feel about that situation , i am i wrong for feeling how i feel ? ADVICE ?!!