Should I confront this little ....?

So I went to this dance Saturday with my guy friend. When he asked me I said 'yeah,but only as friend's' But I told my friend I sorta liked him which I do but not enough to go out with him and she told this girl. So when me and him went I kinda liked him more. He kept touching me and hugged me when I left which he never does even though we are friends. But while one of the slow songs were on I went to the bathroom and when I came back he was actually saying 'help' because this insane girl was all over him. So I told her 'EXCUSE ME!' and he wrapped his arms around my waist and started facing with me. And that insane girl told everyone I was a man stealer! When he was MY date! So the girl mentioned above that my friend told her I liked my guy friend was talking to me and she said "She shouldn't be mad. He's yours anyway. I can't believe she did that just because you were gone" But when I left THIS GIRL danced with him!! After she just agreed with me the insane girl shouldn't be dancing with my date. I show up the next day and this same girl started dating him!!! And everyone was like (let's just call me B and call this girl M) so everyone said to him "Ewww,my are you dating M!! You went with B she's so much prettier than her" and all these guys were saying to me "Your date is an idiot he's chose M over you. That's just gross, M's ugly" And may I remind you M is NOT pretty. And should I be mad at M because we were kinda friends and to be honest i thought she was quiet and it's embarring he chose HER over me. And everyone is on my side with this too. Should I confront her?