Why would a man wear underwear under his bathing suit?

I just don't understand this. While at a pool party this weekend, I noticed several men there wearing underwear under their swimming trunks. I don't think I've ever seen this before and I don't understand it. Okay, the one guy had on white trunks, so of course they would have been see through. But, there's a solution for that. Buy a different color. There's a reason you don't see too many women pulling off a white bathing suit!

But seriously, several of the men. It seems pointless. Is there something I don't know about? So after I got home I tried to do a little research. Kind of hard to find the answers, no pun intended. But I did find an online gay forum where a man asked the same thing. Here were some of the answers:

"Because str(a)ights are getting weirder and weirder"

"That's bizarre... maybe they were borrowing a friend's and didn't want to catch something."

"It took me two years to convince my dad that briefs under the bike shorts and a tucked in jersey is very, very bad. I think it's how straight people identify each other."

"Not too weird. Seems like a lot of swim suits these days; especially board shorts, don't have any liner or support built in. What are you gonna do?"

"I wear boxers briefs under my swim trunks all the time. I ...don't know why. lol. I guess I'm scared to actually get a hard on and won't be able to hide it very well."

Okay, well that may answer that! Seriously, is that it? Hmm... then why is it this is the first time I've noticed men wearing underwear under their bathing suits in my entire life? And I grew up going to the beach all the time and live in Florida. Someone clue me in.

Stylishly yours,
Miss Attitude