Background: It should be noted that this whole conversation was inspired by this
NSFW piece of fanart of Tommy from the Young Avengers.
Miome: It's obvious Tommy doesn't wear underwear.
Tsaiko: It would ruin the lines of his suit.
Miome: I'm sure that's his first concern whenever he has to put on his superhero costume.
Tsaiko: Maybe he takes a page out of Spider-man's rule book.* It chafes.
Miome: *laughs* Although I've thought it would be very hard to hide a boner in one of those costumes. Everyone would know.
Tsaiko: Maybe they're smart and wear a cup under it. Even if they don't wear underwear.
Miome: If there was any superhero in the world that wore a cup, it should be Spider-man.
Tsaiko: Oh?
Miome: What other superhero goes swinging through the air with his legs spread at all sorts of angles?
Tsaiko: *imagines a mistimed swing* THUNK!
Miome: Ouch.
Tsaiko: Maybe this has already happened. It's not like he has kids.
Miome: Even after he's been married for awhile.
Tsaiko: Perhaps it's just as well his genes have been removed from the gene-pool. Do we really need little Spidey's running around New York?
*It has been revealed that Spider-man does not wear underwear under his costume for the reason that it chafes. This is canon. Marvel has the best crack sometimes.