I'm a nurse practitioner, and often workout at our facility after my shift. The other day, I noticed one of the resident nurses had a very visible erection under his scrubs. I tried not to notice, but it was very, very visible.
He excused himself after a follow up, and I didn't see him for about an hour, assuming he had gone to a private area to take care of it. I saw him again after my shift, and was surprised to find him masturbating in an unlocked bathroom stall. I opened up the stall door, to find him standing over the toilet, and his arm moving with obvious motion. He turned in shock, dick in hand, and started shooting his load on the wall next to him. 'Oh-oh Godddd...' His eyes were rolling back in his head, and I quickly shut the door and went to the next stall. I felt aroused myself, because as a fellow man, I know the excitement of shooting your load, especially in a public place.
I sat down, and tried to adjust myself. I saw him shuffling his feet around, and squat down, probably wiping up his mess. Cum was dripping off the bottom of the stall, and I had to laugh a little. 'Man, that was pretty impressive.' 'Dude, I had to take care of it, I've been hard all day.' 'Yeah I noticed.' 'Yeah, I'm sorry man, I should've locked the door better, damn latch.' 'No, it's alright, not like I don't know what it's like.' 'Well, glad you enjoyed the show, haha.' 'Yeah, thanks for the free pass.' He walked out of the stall and I heard the water run, and shut off, and he shuffled away to the changing area. I finished my business, and went out as well. I saw him on a treadmill later, and he nodded and smirked at me. I smiled back, and noticed he no longer had a visible erection.