from www.tmz.com – The sex tape that Kendra Wilkinson claims she’s desperately trying to stop isn’t exactly packed with new material — sources tell us the skin flick was shot back in 2005 … right after Kendra turned 18.

Kendra has already admitted that she knew about the tape — which is now in the possession of Vivid Entertainment.

As for Kendra’s co-star, Vivid president Steven Hirsch tells us the mystery man was the former Playmate’s boyfriend at the time [Ed’s note: he’s from San Diego] — definitely not Hef nor her husband Hank Baskett.