David Duchovny recently entered a facility to treat a sex addiction problem, but was the actor getting some "Californication" on the side? That's false!

According to FOX News, a Duchovny pal says the "X Files" star sought help for his addiction to online porn -- and it didn't have anything to do with cheating on wife Téa Leoni.

MomLogic.com's Dr. Shannon Fox says this type of addiction gets progressively worse until treated. "Like with any addiction, sex addiction is progressive," says Fox. "The things that used to satisfy them are no longer satisfying."