Last night I was at my boyfriends with a coupe of friends we had all had a bit to drink, his 16 year old sister come in who he hates they really don't get on his 18, she asked for £10 to get a cab somewhere they started arguing. All of a sudden their upstairs screaming at eachother a mate went up there and he was punching her to the point her nose was bleeding he was screaming for her to get out. This is honestly never what I expected from him ever I've only been with him 2 months. I don't know what to do? What should I do please someone give some advice x