Josie and Jess decided to lez out after a few beers in vegas. The guys screamed 'Hey those girls are Lezing out'. When they returned home they decided to lez out in the pool with their roommates.
In South Park, it is what they believe girls do at a slumber party...Get naked together and make out. Oh may I add they like to predict the future too.
"Hey Butters, if they start lesing out, just play along."
*in the epsionde which Butters fakes his death and becomes his female alter-ego; Margerine.