love gasket

A love gasket is a moustache and beard or mustache and goatee combo that makes a perfect seal when you give head. This term comes from gasket, a seal used in car engines or plumbing. It's not related to the Brit slang gasket found in Urban Dictionary.

"My boyfriend grew a love gasket for Movember, but it tickled when he tried to go down on me, so I made him shave it off."