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.

skipper flipper by Nutzen YerMouf June 16, 2017

flipper-slipper 

When your tube sock(s) hang off the end off your foot 1/2 way and they fop around.

When children's sock(s) slide/fall down.

NOT to the point of falling off though, just 1/2 way.

'When I got out of bed this morning my socks were flipper-slippers!'

'That baby's got on a flipper-slipper.'

'Flipper-slippers are fun to slide on the kitchen floor in!'

flipper-slipper by Patsea Chema October 1, 2011