Sweaty shorts and pants?

I love sweaty shorts and underwear.
Wearing underwear after they have been worn by another guy is so horny. I love to smell fresh sweat from a guys underwear
(not days or weeks, just a hot sweaty day) the smell of sweaty sticky balls drives me insane.

I also do not mind the odd pre cum stain on them and one of my fantasies is to get pissed on in my underwear. I would love guys to share stories. obviously to gain an insight and research, but mainly to wank whilst reading ;)