Only once, was it a hotel on business and my wife promised she was gonna catch the train up for the night as I was away for a week.
I had just showered and was getting horny thinking of my wife and was getting quite hard.
I hear a knock at the door and thought the time was about right, so guessed it was the wife, and thought I'd drag her in and throw her on the bed and give her some of what we had both been missing for a couple of days.
Unfortunately it was a guy standing there saying I had left my lights on the car and as I hadn't answered the phone (probably cause I was in the shower and didn't hear it) they though they better come up to the room.
when he saw me naked with my cock looking pretty hard, he looked down and said oh sorry sir, your lights are on, on your car, perhaps you would like to get some clothes on first, or would you like me to take the keys and deal with it.
I was so embarrassed, and quickly gave him the keys.
When he returned with the keys, he gave me a cheeky smile as he handed the keys back.
The next morning I saw him going off shift with his boyfriend, they both turn to look at me and smiled.. (don't know if that was a good thing or a bad thing, but at least it wasn't a laugh)..