Mark on bedsheet, left when arising commando style.
you sleep Commando, sit on the edge of the bed n the morning, when you stand up, hey presto, youve left a brownie badge on the bed!
A Fart, strong enough, and pungent enough, to leave a trail up ones back, when escaping.
Mildred, Im afraid you shall have to wash my sunday shirt, I dined with Edward last night, on Guinness, and steak. Im afraid I suffered a "Backtracker"