Why do superheroes wear underwear over their pants?

A question about the superhero costumes that I've had for a long time, guess lot of you like me would have had the same question: Why do superheroes wear underwear over their pants?

Here I got some amazing answers below:

1. Because he can gift his underpants to every hot chick who wants one. He doesn’t need to get naked. This could have been the weirdest reason ever but one of the best too.

2. It’s also said that wearing underwear above pant is "a tradition of strong-men everywhere". Not sure about who said that or in which century but heard some gossip about it.

3. Briefs provide some additional coverage, so that a man wearing tights/leggings appears more intimidating, without adding dangerous baggy fabric.

4. Tights/leggings are practical crime-fighting bottoms. They fit into boots, they stretch, and they're not bulky. And wearing underwear above the tights will be more intimidating and attractive. In polished words, that's how strong-men's costume remains.