Happened twice. We’re doctors and there is a yearly 3 day congress in our field. I’m openly bisexual in my personal life but i was not out at the hospital and since i was in a longterm relationship with my now wife (she knows) everyone asumed i was straight. The first time i went to the congress with the only other guy in my residency year (5 women, two men) and as we were the only two males we shared a room (separate beds). We used to share a room in the residency but the bathroom in the hospital was private and the few times we were in the room at the same time, we kept the bathroom door closed.
So, this hotel was not designed for privacy as the showers were almost facing the beds and the glass door was frosted but like 90% transparent. You could see everything. The first day to break the ice i showered first, undressed sitting in my bed and walked to the shower with the towel wrapped around my waist. At first i was facing the wall and and showerhead so he could see my backside but then i turned around. After i finished he did the same, i could not see him get undressed as i was pretending to mind my own bussiness getting dressed and also pretending not to pay attention to him. I turned on the TV but i was watching every move he made in the shower and his entire anatomy. Average built, smooth chest, trimmed armpits and pubes (but not too much as hair was clearly visible), average uncut dick and he retracted foreskin and stayed like that until he started to dry with the towel. In the next few days happened again and now we didn’t bother to wrap the towel to reach the shower. No comments were made about the nudity situation.
Two years after, he couldn’t come to the congress so i asked another resident, i had already finished and he was in his last year but we met because i was in my third year when he started and kept in contact because i stayed in the hospital as an attending. This time the event was in a different hotel, this one had a traditional hotel room bathroom with wooden door so nothing inside could be seen at least you opened the door. I let him use the shower first, he undressed in front of me but kept his underwear. After he finished he came out of the bathroom naked still drying his head. He was bulkier than me, with a small patch of hair between his pecs, but his armpits and pubes were shaved, his dick was slightly larger than average and fat, uncut but very very short foreskin and almost the entire head was exposed. As he was looking for his clothes i started to undress in front of him. Took everything of in front of the bathroom door (but completely visible to him) and after finished i dried inside. As with my other colleage, no comments were made and during the rest of the stay we made no attempts to cover ourselves.