Tony Parker is a Butt Flasher

Forget coinslots, how about full-on buttocks!

Eva Longoria and butt-flashing fiance Tony Parker ease their pre-wedding jitters aboard a private yacht in St. Tropez, France with family and friends.

The couple enjoyed water skiing together and jumping off the yacht (Tony flashed his derrière while Eva captured the moment on her digital camera).

Tony is expected to appear on the NRJ Music Tour before the couple’s July 7th nuptials near Paris.

35+ pictures inside of Tony and Eva enjoying their last weekend before tying the knot…