My husband is an actor, and I've seen him do much, much more than that... over and over again. I just got over it. Acting is his passion. If he was doing this off-stage or off-screen, that would be a different story.
My advice would be deal. The playwright put the scene in the play for a reason. Don't let your insecurities dampen his creative development. If you can't watch the performance -- or the rehearsals -- then don't go and don't be a pain about it, but don't hold him back. In my opinion, that's not fair.
...and, you might want to think about that part about it "destroying" you. Step back and take a look at yourself... It's not a good idea to let a boyfriend, or a relationship, or anything have THAT amount of power over you.
Answered Sep 15, 2013
Edited Sep 15, 2013
The part that bothers me most of all, I'd like to be in a musical (dream Les Mis) and he said he'd not want me performing kiss scenes, so I see him as being hypocritical the fact I'm not allowed to be upset about it, but clearly he is. I'd told him how I've turned down stuff in the past due to past relationships the guy feeling uncomfortable and that I'd never do anything to hurt anyone. It hurts the fact it seems a one way thing.
The best kind of boyfriend/husband is the kind you can grow with over time. Any guy that you have to limit yourself/turn down opportunities in order to be with is not that guy.