Ben Affleck has been in rehab for just under two weeks and he's already home!

The troubled actor was whisked away by ex-wife Jennifer Garner on August 23, to The Canyon rehab in Malibu during an intervention she staged with someone from the treatment center. But Ben didn't stay ... he headed out of town on a private jet for detox and treatment, where he stayed for the past 12 days.

X17online can report EXCLUSIVELY, that on Friday, Saint Jennifer Garner took time out of her Labor Day holiday with her family and drove to Van Nuys airport to collect her estranged hubby and bring him home. In fact, she LITERALLY brought him home -- he spent the night at her house, with the kids -- their former marital home in Pacific Palisades. That lasted for less than 48 hours and Ben made his way back down the street to his own Pacific Palisades mansion where he is now ... with Playboy model girlfriend Shauna Sexton!

Yep, apparently the two have kept in touch over the time Ben was in treatment and who was the first person he called when he got out?! Yep, Ben's ensconced in his big white house with the 22-year-old hottie and we're watching ... Ben came out this morning, walking right in front of Shauna Sexton's blue car parked out front!