I've never been caught myself, but when I was younger I did catch my roommate. I was 20 and moving in to my first apartment with a platonic friend. I knock on the door, but didn't receive an answer, so I used my key. All the way up the stairs I called his name. When I got to the top of the stairs, I found him laying on the couch with his pants around his ankles doing the "knuckle shuffle". At the time I was rather shy and niave, I'll bet I turned 6 shades of red!:redghost:

Later that night we were downstairs at the neighbor's apartment and my roommate said to our neighbor, "I think your cat got into my apartment this morning, I heard him on the stairs". Little did he know it wasn't the cat at all, but me.