Lauren Betrays Audrina!!!!!

FINALLY! We solved this mystery!

The ultimate stab in the back!!!

Sources reveal exclusively to PerezHilton.com that Audrina Patridge and her former roommate, Lauren Conrad, are definitely on the outs.

“They’re not talking right now,” a Hills insider tells us.

So, what exactly happened????

That’s where it gets tricky!

Here’s what we know thus far…..

Apparently, a friend of Audrina’s on/off boyfriend, Justin Bobby, told her one night that Justin and L.C. hooked up.

“When confronted, Justin admitted to Audrina that he and L.C. hooked up,” a source tells us.

This “confession” only happened within the last week, we’re told.

Lauren is, of course, denying everything to Audrina, but “Audrina doesn’t believe L.C. She knows something happened.”

Ohhhh, the drama!

This might all be too real for The Hills, though. We’re not sure if this betrayal will make it onto the show.

More details to come hopefully. As soon as we know, U will know!

[Image via WENN.]