What would you do ?

​ I've never had a close relationship with my father .. He really never cared to be apart of my life growing up . This past weekend he invited my husband , my son and myself to go to the beach with him so we went ! At first we were having a great time but than on Saturday night we went to eat . Keep in mind that I had been keeping up with my 14 month old all day on the beach and pool by myself while my husband and dad were deep sea fishing . (That gets exhausting by yourself ) not to mention I'm pregnant & hormonal . So when my husband and dad got back to the condo I was anxious to give my LO to my husband so I could relax some myself . Something I said offended my husband and we had a little argument ! We got to supper , and my dad had been drinking all day .. He was probably drunk but I was oblivious to it because I'm not around that type of behavior EVER . Me and my sister got up to go to the bathroom and when we get back my husband is gone and my dad is calling him a bitch , and really down talking him to me while I'm holding my son . So unaware of what is going on I jump up to find my husband ..! DH hadn't been talking much at dinner , which that's just his personality he is quiet & for some reason it made my dad mad . We are standing by the car and my father came outside acting like an idiot cussing and raising complete hell with DH while me and my son are standing there ! He than had the nerve to HIT MY HUSBAND multiple times in the face ... while me and my child were standing there .