Justin Bieber, Selena Gomez ... We're Not Back Together ... For Now

Selena Gomez was front and center at Justin Bieber's concert Wednesday ... but our Selena and Justin sources say they are not back together ... but both sides say things are subject to change.

Selena and some of her girlfriends showed up to the Staples Center concert, and we're told after the show Selena jumped in Justin's SUV and he took her to the place she was staying for the night. But that was it. Justin left and went to party with Kanye, Kim, Dave Chappelle and Nate Diaz.

As for what it means ... we're told Selena says she is not romantic with Justin and it's not in the cards.

Here's the thing. Our sources on both sides say they both have unresolved feelings toward each other, and although they're not hooked up now ... it could easily change, the way it has in the past.

We're also told there's a practical obstacle ... both Justin and Selena are going to be on tour for months, and realistically they can't be together.