Similar to acts such as the wet willy. Termed a "slug", this act is a trick played on another person in which you drag your fully extended tongue across a portion of the unsuspecting victims bare skin, leaving a slime trail.
Ewwww I hate it when you give me a slug when I'm trying to sleep! (the phrase slug lick isn't used to describe the act)
by Sh0ckerturb0 November 16, 2009