I work the overnight shift at a hospital and a lot of nights it is pretty slow. All I really have to do is get paperwork sorted and check patient stats in their rooms. One night I was making my rounds and when I walked into one of the rooms, I saw an older patient with his gown up stroking a very hard, very large penis. It had to be at least eight inches long and it was fat. I don't think he realized I was there because he didn't stop, and I couldn't pull myself away. I stood there for a few minutes until his hips started moving around, and then I saw a huge load of cum shoot into the air and run down his massive cock.
As soon as this happened, I walked back out of the room as quietly as I could, and when I got back to my station, I could feel I was very wet. I couldn't get the image of him out of my mind, so I snuck out to the bathroom to masturbate. I locked myself in one of the stalls and dropped my pants to my feet, leaving my very wet pussy out in the open. I sat down and started rubbing myself as fast as I could, moaning and breathing hard the whole time. At that point I didn't care if anyone could hear me, so I rubbed and fingered as hard as I could. I kept thinking about his hand massaging his penis, and when I saw the cum shooting out, my orgasm hit me and I almost slid off the toilet onto the floor. After I wiped myself up, I saw how wet my underwear was so I took them off and stuffed them in my pocket and went the rest of the night feeling much freer.
The next day he went home so I didn't get a chance to see him masturbate again, but hopefully pretty soon I will walk in on someone else.