David Hughes from Penmaenmawr previous owner of a bunkbed and a viz mag was taught by a close relative how to slat wipe.. Basically tossed of by your uncle and then wiping the cum on the slat of a bed belonging to a sibling..
An invitation to someone's bed to get busy (from the wooden slats of the bed frame.) Often used in a situation where nothing else is desired but a casual encounter but the user wants to use a term less obvious than 'booty call'.