After beginning a surprising romance in March and going public earlier this month, Jennifer Aniston and Justin Theroux have already taken a bold step.

Us Weekly says they have, anyway. That step is moving in!

"He's living at her place in L.A.!" an insider says, but regardless of their new living situation, this is clear: "She's introducing him as her boyfriend."

That's a big deal for Aniston, who is notoriously guarded and hasn't been open about any of her beaus since her 2008 split with some douchebag.

Theroux kept a room at Hollywood's Chateau Marmont before taking up residence at Aniston's posh place, reports say, plus an apartment in NYC.

That place is all his after girlfriend Heidi Bivens peaced after her relationship of 14 YEARS dissolved. She lived with Theroux for the past six years.

No idea how they ended things or whether they were on the rocks already, but Jen sure seems happy with Justin now. Hopefully it's for the best.

[Photo: WENN.com]