Track meet or frat formal?

I'm in college and have a track meet the same day as my boyfriend's fraternity formal. I really want to go to the formal, because it's his biggest event and he seems really excited for it, although he said he wouldn't go if I can't. Plus, it would save his good buddy money on the hotel room. But I'd have to lie to my track coach in order to miss my meet - I'm on a modest scholarship to run in college. There are several other meets, and this isn't a super-important one. I just don't know what to do, either way I'm going to feel bad about letting the other down! ANY advice/tips would be great. thanks