Sorry, he sounds a little like his life is out of control.
Sure bunnysoprano OP could go at him hell for leather, but it'd only inflame the situation.
Men are like that, they get stressed, they get nasty. We might not like it, it may even be wrong, but it happens. It doesn't make any sense, but men in general don't actually make much sense most of the time.
I agree, he doesn't perhaps deserve a bit of pandering, but in some sort of messed up way, that's what he's asking for.. with the you don't love me anymore comments and irrational behaviour at wedding. Men can get emotional too, even if they can't actually deal with their feelings.
It's worth a try, for OP to sit down, hand on knee and say what's up you silly bugger, of course I love you... The fact that he hasn't said anything to her today could even be embarrassment.
So yes his behaviour may be being totally counter-productive, but if OP dissarms him with kindness, perhaps he'll get over himself and open a dialogue.