My brother boned my wife

My(17m) sister(22f) and brother(20m) came up to visit for the holidays. So me and my wife(17f) were in the living room watching tv with my sister. My brother was in the kitchen, he shouted at me to come over, I said ok, he said again, I went over to see what he wanted, he told me to shut the back door, I asked why, he told me he wanted to show me, I shut the door and he pulled his erect D out of my wife's mouth, I got mad and punched him in the face and called him a sick incest fuck, he said it didn't matter, that she wasn't my wife yet and that she was just his little play thing, I said coz you're my brother you think you can do anything you want? He said yeah coz you're just a kid, I got more mad and kicked him in his balls, he doubled over and fell to the ground screaming in pain, my sister and wife came in, my sister asked wtf I did to her brother, I told her he was screwing my soon to be wife, she called me a liar, my wife said I wasn't lying and that she was sorry, my sister yelled at her and said she was gross, a whore and that she was going to tell our parents and that they wouldn't love her anymore, my wife cried and said she didn't care and went back inside, my brother eventually got up and left, my sister left too, I asked my wife how long they've been together, she said a few years, I asked her if she loved him, she said no, I asked her why she did it then, she said coz he made her and coz she loves me, I asked her if she still loved me, she said yes, I said I didn't love her anymore coz she hurt me, she cried and said she was sorry, I said it was too late now and told her to go back home, she said she had no where to go, I said so you thought you could cheat on me with my brother and still have a home with me? She cried more, I told her to stop being a little bitch, she said why are you being so mean to me? I don't even love him, I said you're a disgusting whore, she said I'm sorry, I said you're not sorry, if you were sorry you wouldn't have done it in the first place, she cried louder now and said she didn't care and went back inside the house and to our room and slammed and locked the door.