It's when you stick one finger in her pussy and another one in her ass, then stick either one in her mouth and see if she can guess which hole it was in
"Last night I told my girl if she wanted to do the pepsi challenge and she said yes. So I stuck my index finger in her pussy and my other index finder on her ass. She couldn't tell which one was in what hole"
by aztec87 March 20, 2012