On a boat, in a 69 with a lass i'd only met but a few hours previously, but we had taken over a friend of mine's cabin, as mine was currently occupied by a friend and his gf.
So, we're going at it hammer and tongues *cough* and suddenly the door opens, it's the friend just returned.
My dick is half way down this delightful young lady's gullet, and she oblivious to the intrusion, so it's left to me to shout:
"GET OUT OF YOUR ROOM!!!"
At him.
At which point he closes his mouth, mutters "ok, ok..." and back out of the room...
I think he had a lady wth him as well...
Oops.
The lady I was with that night was a long distance squirter...
Oh happy days.