Why are Tighty Whities made fun of so much.. where does the Stigma come from?

[demrob11]

[ConnieS]

I think it's the name that might sound funny to some people.

White underwear is sometimes associated with someone who's a "good boy" or a "good girl" and (as we know) some men are made fun of if they're "good boys"/vanilla/not promiscuous. Maybe that's where the "stigma" comes from.