With all due respect, it seems to me like both guys are completely over-reacting and a bigger deal has been made of all this than really is necessary. Everybody should go to the wedding who was supposed to go, and they should all do at the wedding what they were supposed to do. It's that simple.

If there was any mistake made at all here, it was probably your friend not asking her boyfriend what he thought of her going to a strip club. Still, I see it as only a small mistake. A strip club is a common venue for a bachelorette party. I don't see why its that big a deal (especially if there was no nudity). If your friend's boyfriend is offended by such things, then just respect that he is offended by these things, accept the mistake was made, apologise, and move on with things as originally planned.

I hope your wedding goes really well and its a fantastic day for you, and to quote Napoleon Dynamite, "I hope your guys's experiences are unforgettable".