Seems a lot of people enjoy the stories from Doctors, and since I spend most every morning supervising masturbations, thought I'd share!
I work in a fertility clinic, and masturbation is a daily event there. Men need to have their sperm checked for viability, and this requires them to provide a sample. Since sperm viability testing requires the temperature of the sample to be controlled, it has to be 'given' at the clinic, not 'supplied' from home. The guys have been given the drill before the 'deposit' visit, which basically is they will be provided a private 'comfort room' , and a 'deposit cup', and are told to not ejaculate in the 48 hours prior to the sampling. When they arrive, they are taken to a room which has a bed, a lounge chair, and a sofa. They can use whichever makes them most comfortable. I enter the data into the computer, along with the time of their last ejaculation, print out a label, attach to the cup, and tell them to place the cup on the cabinet when they are done, and to press the call button. They are told that lubrication is not allowed, (can taint the sample). They also may not have their partner present (Eliminates a lot of variables. The sample needs to be unadulterated, and despite instructions that they need to masturbate for this test, many men will decide that they need to have sex vaginal or oral to climax because they dont want to admit to their partner that they can or do masturbate. Body fluids from a secondary person can invalidate the test).
Now to the fun part. You walk back to the station, and you know he is in there whacking away. (we provide 'tasteful' sex magazines to help with the mood). Sometimes, the call light is on before you get to the station! Under a minute! Sometimes they are in there for a half hour or more, obviously having issues with the whole idea of shooting into a cup, with everyone knowing what they are doing. On rare occasions, in their excitement, they completely miss the cup, splattering the floor or whatever, and they are trying to crank out another shot. Since that affects the results, they can't do that. So if the 'event' takes more than 15 minutes, we have to ask and make sure they only ejaculated once. But on average they do the deed in about seven minutes. When I return to retrieve the sample is my favorite part. some guys are still sporting obvious boners in their pants. Tight jeans, or even worse, knit sweatpants show the most obvious erections. Some are matter of fact, most are embarrassed as hell, a rare few seem proud of their accomplishment. You quickly check the cup to make sure you have enough semen for the test, and then send them to reception. After they leave, you check the room to make sure there is no semen lurking on the bed, floor, chair, magazines, etc. (and believe me, we've seen it in some weird places) and then the room is cleaned by a janitor for the next 'guest'. You do a second 'cum check' to make sure he didn't miss anything, then escort the next patient.