Real Reason Superman Wears Extra Underwear by Epigeus on DeviantArt

Secrets of Superman's Underwear by techgnotic on DeviantArt

What is the origin of Superman's design? Why does he wear red underwear over blue tights? - Quora

If Superman is really so masculine, why is he wearing his red underpants over his pants? - Quora

If Superman is really so masculine, why is he wearing his red underpants over his pants? - Quora

If Superman is really so masculine, why is he wearing his red underpants over his pants? - Quora

SUPERVIXEN VS SUPERMAN by superbabsy123 -- Fur Affinity [dot] net

Comics] What is the in-Universe reason for superman wearing underwear on the outside? : r/AskScienceFiction

The real reason why Superman wears his underwear on the outside (check notes), Superman

Finally learned to wear underwear inside, Superman

If Superman is really so masculine, why is he wearing his red underpants over his pants? - Quora

Superman returns suit, no logo or underwear by Spider-maguire on DeviantArt

The real reason why Superman wears his underwear on the outside (check notes), Superman