Conflicting AP's

So i'm pretty irked because my ap environment class has a mandatory movie night the same night as a mandatory formal dinner for ap us both to review for the coming ap tests. I'm not sure which to go to...should i go to the class i'm less prepared for or the one i like more? I feel like i'd be more dissapointing to my classmates and teacher if i skipped the ap us event. Who knows....any thoughts?