skipper flipper
When a woman is bathing or swimming naked and her labia ebbs and flows with the current of the water. Usually occurs in a woman with an above average size labia.
Beth and Tommy decided to go skinny dipping at the lake. They stripped down and entered the cool morning water, wading out until it was up to their waists. From nearby, they heard an old man laughing. They turned and looked real quick and noticed a man on the shore fishing. He said to them, "Holy shit girl, you have some mighty long vagina lips. You got a skipper flipper going on there." Beth screamed, Tommy laughed with man.