Yes, I have, many times. I, absolutely, love walking in on my wife while she's sucking or fucking her bf. She knows this, so she makes sure that happens as often as she can.
As an airline pilot, she knows my schedule. If her bf will be at our house when I get home from a trip, she lets me know. Most of the time, they are going at it. If they are in bed asleep, I will just strip and slide in bed with them.
There were a few times I came home and my wife was fucking two guys. It was her bf and his friend.