This happens when a dude that has braces on his teeth is going down on a girl that is quite hairy in the nether lips and his braces get ensnared in her pubes, thus locking his face lips onto her downstairs lips.
-Hey, did you hear about Timmy?
-Yeah, I heard he went down on that random girl at the party, and they got lip locked.
-I guess that's why you need to check before you munch.
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)