I was out of town and was at the spa. The dressing room was shared with the health club. It was the middle of the week and I was alone in the dressing room. In walked this very hot guy who had just finished working out. His locker was next to mine and he stripped off his clothes (not facing me) and left his clothes in a pile on the floor.
Something came over me and i picked up his sweaty underwear and I brought it to my face and smelled it. It smelled so raw and my cock got hard instantly. Here I was in the dressing room, naked, hard and smelling his underwear. And then I took the crotch area and put it in my mouth, sucking his sweat from them, so nervous I would be caught.
i was lost in complete ecstasy and realized in the nick of time that he was walking back. I dropped his underwear and tried the best to hide my little hardon. I have no idea if he saw it and saw what I had done but he gave me the funniest, most humiliating look I have ever seen. And I jerk off to this all of the time.