one who is extremely vulnerable to orgasms and upon obtaining said orgasm feels a surge of energy through their legs causing them to split apart violently.
"Brennan, that girl you dated must have been a leg splitter" said John.
when your doing it to a girl whos legs are pointing at about a 120 degrees angle, they you grab her legs and pull them apart as hard as possible. this will not only feel great, but it will also pull her hamstring. (depending on how hard you pulled)
"when i was doing your mom last night i did a leg splitter..."
"i think shes dead"