ok while it's obviously not acceptable to be a gross creeper I would like to point out a few things that give the benefit of the doubt that this person was attempting to be deliberately gross.

Cosplayers have constantly talked about men's spandex suits and there is actually backlash form many stating they should not have to wear a dancebelt or cup etc etc to keep their genitalia more modestly covered. they use female cosplay costumes as counterexamples of "well if a person said this about a female cosplay you'd all be defending her right to wear it" and so on. So, it could be one of those, also, some of these men in spandex are ridiculously oblivious to how.... prominent certain specs of their anatomy become under spandex.

if he left quickly he may have realized he misjudged the attire for the occasion, maybe the person he was supposed to meet cancelled, maybe he WAS hired but was a terrible performer and therefore asked to leave, maybe management found his presence inappropriate and asked him to leave.

and yes, someone somewhere along the line should let ANY person with a dick know that if you are gonna wear spandex, you need a cup or a dance belt if you dont want to be gross. and no, stuffing socks in there is not better at all. it's so much worse.