I have been caught three times and caught someone else twice.

First time was my big brother walking in on my getting a blowie from a girl a few doors down. He just laughed shut the door and shouted "nice one bro". She carried on like a champ and didn't seem phased.

Second was me mid thrust doggy style, mum walked in. She just gasped, said sorry and quickly shut the door. The only reference made to it after the fact was "were you both sensible?" And me answering yes.

Third time was me eating puss, and her friend walking in. She stood around for a while quietly. I took my shot, asked if she wanted to join in, she was up for it. Other girl wasn't. Didnt get a threesome.

I caught a friend shagging his girlfriend, said sorry and left.

Also caught my parents having sex. Ran out the room and never spoke of it again.