<human>: Can you condense the text into a few key points?

My friend asked out a girl to homecoming about a week ago. the problem is she wants to go to homecoming with a date and not with him. to elaborate she said yes although she doesnt want to go with him.

  So my friends want to tell (lets call him O) that she (lets call her S) didnt want to go with him AFTER homecoming and i think that i should tell O now or i could talk to S about it and tell her that if she doesnt tell O the truth me and muy friends will. and then i will tell someone with an influence of gossip to spreed the word that she used my friend. 
   Im still not sure what to do but i think you guys can help!
<bot>: My friend asked a girl to homecoming and she said yes but is using him as a date to homecoming and doesnt really want to go with him.