Ah stress--that trickly little bugger that will get us again and again, no matter which direction our lives turn.
And it only seems to get worse with time. I'd love to go back to the stress levels I had in highschool or college (with the knowledge I have now, of course)--my problems then seemed so minor compared to working about how to pay the bills, health coverage or a whole slew of other "adult problems" (it's hard being an adult when you haven't quite decided to grow up yet).
But to be fair, highschool and college could be quite stressful, and mostly because at that point, I hadn't quite learned how to deal with stress.
Now, I've noticed that you have had a few comments to make in recent days about the fairer gender -- and while not wishing to disparage the females that you are friends with/attend school with-- I would like to assure you that as we get older, we do mature, and we aren't quite so bitchy and catty as we were in highschool (now that is not to say that everyone was bitchy or catting in HS or that everyone grows up).
As for the girls who are making your friend's life hard, I'd say he just needs to be honest with them--come straight out and tell them that even if he was interested in them, their behavior makes them very unattractive -- that will do one of two things--they will either never speak to him again out of rage (problem solved, he can go to the prom in peace), or they will be mortified and reconsier their behavior.
Sorry, I got a bit long winded there...