lip splitters 

when a chick wears jeans so tight they split her pussy lips apart

god damn jenna was wearing some lip splitters last night

lip splitters by mikeyc18 April 28, 2009

lipsplitter 

One who derives great satisfaction from and has gained a reputation of punching others in the face in an attempt to draw blood in an attempt to gain significant physical and/or mental advantage during a fight. Typically a person who is participating in a (full) contact sport which involves significant physical contact between the athletes involved. Examples are: mixed martial arts MMA, Muay Thai, judo, karate, kick-boxing and or prize fighting.

This fight is going to be messy and won't likely last long because that guy is a real lipsplitter.

lipsplitter by Brad Keith April 8, 2008