My dumbest/unluckiest was after I picked up a girl and took her home. My girlfriend at the time had let herself in but was sleeping in the lounge. We snuck past her and upstairs to my room. After a few minutes I hear my girlfriend coming up the stairs, so I tell the girl to stand behind the door and to sneak out while I engage my girlfriend. This worked well and a few minutes later I hear a car drive off. My girlfriend then said to me "she could have stayed".
