Is She Really my friend!!?

okay... just yesterday at school it was a normal day everything was going great, me and my friend was walking to our cl (she is in the same cl as me) my boyfriend sits beside her and they started to flirt when i walked down the room to sharpen my pencil she purposely knocked my pencil out my hand and walked over and bent her over near my boyfriend then started to laugh i thought she was just playing but in the cafeteria they they was laughing and giggling now it went too far.. now today shes tryna be my friend all of a sudden, should I stay friends with her and forgive my boyfriend yes or no HELP my friend really says shes sorry and my boyfriend says hes extremly sorry for what he did so please HELP!