Jump Rump 

A perverse naked form of leap frog.

I saw 3 drunk girls playing jump rump in the snow and couldn't look away

Jump Rump by oninomad February 22, 2011

Rump-Jump 

Invented by a group of South Florida teenagers on a summer afternoon. Rump jumping is to get completely naked and jump from a structure such as a bridge into a body of water. The higher the jump or the busier the bridge, the better. Often done in the pursuit of Instagram likes or simply a good time with friends.

Sarah: "Theres no way you'd rump-jump off 17th street Causeway into the canal..."
Matt: "Anything for a good laugh and some Instagram likes, grab the camera and lets go"

Rump-Jump by killemandgrillem69 November 14, 2013