Superman wearing his underwear on the outside is one of the oldest superhero jokes of all-time. There are a bunch of reasons why he’s designed like this, ranging from being inspired by circus strongman outfits, to his actions being easy to understand at a distance when drawn.
Warner Bros. and DC would eventually try to ditch this aspect of Superman’s duds. Beginning with the New 52, Supes lost his red underwear, a design choice that would continue in the Man of Steel costume design. Thankfully, in recent years the red underwear is back, and one fan has a fun theory as to why it’s a key part of his ensemble.
The conceit is that Martha Kent has always traditionally made Superman’s costume out of Kryptonian cloth. But what if it’s indestructible? This would mean she’d have to fashion something from a single sheet of fabric, so what if the red underwear is the only part of his costume made from the blanket he arrived in?
It would explain why whenever Superman suffers battle damage his underwear is never blasted away, which would naturally affect his upstanding reputation as a family-friendly superhero. Replies agree, with some saying they came in skeptical, but “as I thought about it more it actually started to make sense,” and “I was prepared to laugh and ended up agreeing with this”.
We’re down with it, too. James Gunn is currently preparing his own take on the character in Superman: Legacy, and if he needed some inspiration on where his costume came from, this fun fan theory may be just the thing.