Should I confront her?

Tonight we were out with friends. My best friend motioned for me to sit with her. The only spot left was with my SOs best friend so that's where he went. His best friend kept touching him (non sexually) all night. She was pretty drunk. Like her hand on his leg. He kept pushing her off but she would keep doing it. When we got back in our car, we both kind of looked at each other and said that was uncomfortable. He offered to talk to her tomorrow and text her right now but I told him not to. Should I confront her? If so, how? We are pretty good friends and she's never like this when she's drunk.