Pussy Rub
Vaginal sex for lesbians.  One lays on her back with her legs and ass in the air, legs spread, and the other stradles her on her knees, and they rub there pussies together, cumming all over and inside of each other.
Dude!  You should've seen it last night!  Me, Kelly, and Jenn went back to my house after partying all night and Kelly and Jen were pussy rubbing right in front of me!