They became "gay" as far back as the 70's, and if you look at really old vintage pics, you'll see the equivalent of jockstraps more than a century back.
As it became safer to be gay, the jockstrap became a fetish item: it evoked images of "manliness": strength, muscles, cocks and balls pouched up an emphasized so you couldn't take your eyes off them, locker room "guys" chatter, competitive spirit (like a warrior), etc.
I think it's disingenuous to expres surprised that jocks are "gay," even tho I deplore that attitude. What makes jocks sexiest to me is when the dude thinks of them as athletic supporters. That is, he just pulls it on to protect his cock and balls and the last thing he's doing is "preening" for other guys, which is what "fashion jocks" try to do, which is why I hate them. The lack of self-consciousness is what makes them hot.
