in extreme cases it can turn so sticky the lips will be glued together and flys will stick to it so watch out.
another common cause is talking the biggest load of shit.
its more commonly found amongst gay men who love to rim filthy asses.
remember always wash your lips!!
penny : i dont wear lipstick
lenny : well what da fuck it that shit on your lips?!!?
Benny : eeeeeeeeeeewh theyre mouthskids dirty fuckin bitch!!!
Lenny : WHAT??!! YOU FUCKING BITCH!!
Jenny : im sorry!
benny & lenny then kick the mouthskids off and skull fuck jenny. she loved it.