Do you wear anything under swim trunks?
In general, you should never have to wear any underwear under your swimsuit. ... If it is swim trunks, swim shorts or swim briefs, you usually shouldn't wear underwear underneath those either. Many people may want to know why you shouldn't wear any underwear under swimsuits. Isn't it too revealing and uncomfortable without additional cover? In reality, you are more covered up than you think you are. Here are more details about how the swimsuits are built to act as both under and outerwear.