It's their day, they can do what they want.

Alright, that is true. I just don't think awkward pelvic thrusting infront of 200 people who are watching your special dance is a good story to tell down the line.

Screw tradition. I'm dead set on having a flash mob at my wedding.

Yes, it's their wedding, but timing is important, too. It wouldn't have killed them to do a traditional first dance and then segue into something silly. Choice of song is important, too. "I'm Sexy and I Know It" is just annoying, and while they were trying to be funny with silly moves, the whole thing probably came off as selfish and thoughtless. Remember, they said nobody laughed-that would include their same-age friends, not just older relatives.

It also wouldn't have killed the guests to be more supportive of what they wanted on their special day. What's the point of doing something traditional if it's not what you want to do?

Speaking of friends their age, would you not have at least a couple friends with the same sense of humor as you, who should have found it just as funny as OP did? I once had a very elaborate, fake wedding to a girlfriend of mine. And while some of our friends called us crazy and asked what the hell we were doing, some of them were our "bridesmaids" because they also thought it would be fun. OP should have friends like that and they should have been laughing.

I agree with #47: My cousin and her husband had "Losing my religion" as their first dance, and it was really awkward since she had recently converted to Islam due to her husband being Muslim... Most of my family is Catholic, so they were all staring at the dancing couple like "WTF?!!!". Then it got "better", when they passed Katy Perry's "Hot and cold", as all those who had seen the clip were looking at each other, in a "WTF mode". Oh yeah, and the best part were the slides the bridesmaid had put together, with the melody of a French songs which basically says "why are you screwing up your life?" I'm not conservative. I just think that the atmosphere would have been less tense if they had done it in a more traditional way. An to go back to the FML: we don't know OP's relatives...their not laughing doesn't mean they are not fun... I don't even know if I would have laughed...

That's what I was thinking, I wonder if its on YouTube yet!

I checked UTube; there are several "Sexy and I Know It" first dance videos. So not only did they do something embarrassing, it wasn't even original.