It means to make-out voraciously.  Term is used more when people see you doing it publicly.  Not necessarily a bad thing but people say it more disparagingly.
by Primadonna August 10, 2004
 Get the suck facemug.
Get the suck facemug. by Adam August 10, 2004
 Get the suck facemug.
Get the suck facemug. I had to look at the clock, I had no idea what time it was because we were sucking face for so long.
by Posie August 10, 2004
 Get the suck facemug.
Get the suck facemug. to kiss for a long period of time, may include (hopefully) some biting and licking of the neck and ears. non-pretty way of saying make out.
Nineteen-year-old Louisa Almedovar and her 22-year-old boyfriend Rich Langley, both of Vineland, New Jersey, USA, sucked face non-stop for a record 30 hours, 59 minutes and 27 seconds on December 5, 2001
by alrae June 29, 2003
 Get the suck facemug.
Get the suck facemug. by Meemo August 9, 2004
 Get the suck facemug.
Get the suck facemug. by heather August 10, 2004
 Get the suck facemug.
Get the suck facemug. by Amy August 10, 2004
 Get the suck facemug.
Get the suck facemug.