I have done that in a hotel when room service guy comes in. very erotic.
A few years ago I was staying in a hotel. As normal, I went down to the pool area after work. Once done I went to my room
to shower and order some food to the room. After placing my order, I turned the shower on when my cell rang and had a quick chat. Room service is normally pretty slow, so after my call I was about to jump into the shower when there was a knock on my door.
I grabbed the hotel bath robe and opened the door for the room service guy. A little side note, I wear ball weights with a pretty long hang.
The guy placed the tray on the table. I sat down to sign the bill. He was standing next to me, when I felt my robe slip open a bit. I
thought what the hell, this could be interesting. As I took my time filling out the bill, I moved my leg a little, sure enough, the robe opened right up. There I was sitting as if nothing happed, with my cock and balls hanging out for him to see. He stepped back to get a better
look. Once I was done, I stood up, and the robe closed up. Nothing else happed but he smiled on his way out,
First and only time I did this at a guy, It was sort of a personal dare, that I really enjoyed more tha I thought I would.