Ok first and foremost I dont think it's fully on her. I think there are TWO sides to this story.
If you all didn't read she had asked him to try out for the play and ask friends to join too and he turned around and said i'm not your ***** and she said yeah you are.
Ok right there its BOTH there bads. He snapped at her, when she really wasnt doing anything wrong, so she got pissed and snapped back.
Their problem is they fight fire with fire (apparently both very passionate people) instead of difusing the situation they heighten it. Its two ego's clashing. Something all of us are guilty of from time to time.
But I agree with what someone else said, even if it's true that you all DID seem to have feelings for each other, unless u all learn how to react to each other better its NOT worth getting back on that rollercoaster. It's just going to continue to hurt you both.
Unless you all learn how to be more civil with one another which would have to be an effort on BOTH sides. since BOTH sides seem to have caused the trouble. And only if both are willing to take that step will you all be able to work. If not you all will continue to clash. Either way it'd be something you'd have to discuss with her.
Like you already said you dont feel like putting the effort in, and you have every right not too. So since you dont, just back away and let it go. Sometimes it's a hard thing to do if you still have feelings for someone, but if you arent going to put in effort (or if she's not willing to put in effort as well) then it's never going to work out, and it will forever be a rollercoaster and just wont mix. Simple as that.
Enough with the blame game already, both people were wrong. It happens, that's life and a part of relationships sometimes. The real relationships that last are the ones where people learn to get past that. If it doesn't happen then it doesnt happen and o well it wasnt meant to be. on to the next, you all had your good times and your good memories but that's in the past.
Just do what you feel is best for you. End of story
"Too bad stupidity doesn't actually kill"
"No fear. No distractions. The ability to let that which does not matter truly slide."^"I say never be complete...I say let's evolve." ** Fight Club**