What should I do with my 'Friends'?

I was at my friends house with another friend. We were on a trampoline and they started wrestling around...and before I knew it Conshie (one of the friends) slapped Connie (the other one) and called her a *****! Since then they've been fighting. And Connie has been willing to physically fight because Conchie has actually been touching Connie! Like hitting her and stuff. I just don't know what to do. I'm really mad at Conchie and I'm just afraid that they'll become friends and Conchie will end up tricking Connie into ditching me. What should I do?