When I went to the lake I noticed a lot of boys wore underwear under there pants (mostly teenagers) I asked my friend that's a guy about it but he said ask some other guy I don't know why they do that can someone explain?
Never known any guys that do that (not that I've asked them what's under their bathing suits, mind you).
Some board shorts don't have an inner lining. If they don't, they plaster themselves to you when they get wet. Your bulge is prominent, the suit can chafe like all hell, and thin suits become see through if they're white. I suppose in that instance, it would be a good reason to wear boxers. Also, if they're particularly loose around the leg, it's an easy opening to showing your junk, so I suppose that might be part of it as well.
Board shorts without a liner suction up to you when you get out of the water completely showing your junk. Also if the shorts have white on them, especially in the groin area, they become see through when wet.
I had no idea my own gender did that. LOL I actually prefer swim trunks that don't have any inner netting. I imagine it would be super uncomfortable to wear underwear under a bathing suit, because the fabric of underwear would absorb water and be very difficult to dry out. And that could cause nasty skin rashes.
It doesn't make much sense really. But I think it probably has to do with their feeling insecure, or nervous about getting an erection and they want another layer. But why on earth would anybody want wet cotton underwear on under a swim suit?
1. To keep things from rubbing together and chafing 2. In the event that the top suit falls off, everything is still covered 3. To prevent the butt crack from showing if the top suit slips (this is apparently different than reason #2)