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.
-True.