Snailing is the act of Jizzing/Cumming on a girls face, Then afterwards turning your balls over your penis to give the impression of a snail, Then proceed to plant it on her face and rub the jizz around in a snail fashion.
Directed towards males: when a male's penis comes out of the designated hole made in the boxers.
Ever had a pair of boxers that feels like the hole in it is a cave? Happened to me this summer and decided there has to be a name for it. Figured out there was not so I came up with "Snailin' or Snailing." You are running around and your penis just keeps coming out of that hole.
An act in which a male or female licks their partner from the bottom of the snail trail area on the stomach all the way up to the lips as a sexual act.
e.g
guy 1: what were you doing last night dude?
guy 2: i was totally snailing this girl guy 1: omg no way you snailed her!