WHAT THE HELL IS SHE THINKING?

alright so i went to a sweet 16 tonite, and i was hangin with my friend talkin about what i was doin yesterday and stuff. and my ex (who i never wanted to talk to ever in my life again) was with her friend and she was behind us. and when i was talkin her friend takes my ex's hand and jumps in my convo askin "what happened" i said i was walkin around ouside yesterday. and i went by your house (my ex's friend's house) and she was "oh i wasnt there i was with (ex name)." i was oh it was your birthday right? and my ex said ya. i said "happy birthday." she said "you know yesterday wasnt my birthday." i said "i know" then they left to get somethin to drink. it was a really awkward. then when every1 was dacin i was chillin with my friends. and i could see her look at me alot. i mean i was makin alot of attention but alot of people didnt bother to look over at me but i could see she did. BUT the thing is she has another boyfriend now so what is goin on?