I remember that situation well, I was around 25. First wife had fertility issues, so I had to give a sample to verify I was good. On day three I went to my construction site, trying not to think of the up coming event, but the field office secretary knew of my situation and she kept giving me cleavage shots all morning. She was a crazy mid 30s gal. Got to the hospital, found the lab, they lead me to the nurse lounge that had a bathroom and couch area. Cute nurse pointed to a box and said “if you need some excitement, these might help”… the box had Playboy and Penthouse magazines. I decided to get to it, dropped my pants and underwear to my knees and began to stroke, rock hard in no time. About a minute into jerking I hear a knock on the door, then realize the bathroom had two doors and I panic. It was the nurse saying “ I forgot to tell you to use the cup with the white cap “. She was laughing as she knew see was interrupting my mission. So, two minutes later I blew multiple shots into the cup, sort of proud of my load. Took a few minutes to gain composure and take the cup out to the nurses desk. Older nurse took the cup and said “did you mess up the bathroom, did you clean up any missed shots? “. I had a look of horror I guess and said, “ no, it’s all in there”. I pretty much turned and hustled off. She then yelled down the hall for me to come back. I did and she asked “ how many wanks did I do ? “. Huh? Well that’s a lot of semen in the cup…Me, “ um, just once mam”. She then just smiled and said “ ok, you can leave”. Mortified and feeling that post cumming euphoria was so weird as I exited the hospital.