Are you supposed to wear underwear under men's swim trunks? If so

Is it good to wear briefs to swim? - Quora

Can I wear men underwear on my period (I'm a girl) because I heard it has more space and it's more comfortable? Should I? - Quora

What are your thoughts on men's swimming trunks, such as board shorts, in terms of style and comfort? - Quora

Why don't men widely use bikini briefs for swimming? - Quora

Can men with incontinence wear the Always Discreet underwear at night, etc.? - Quora

What is the right occasion to wear men's bikini underwear? - Quora

Where online can I find patterns for men's swim briefs? - Quora

Can a man wear spandex briefs, shorts, or square leg shorts? - Quora

Are you supposed to wear underwear under men's swim trunks? If so, which type? - Quora