So Why Did THESE Two Split?

Was it because Miley's going to be shooting The Last Song in Savannah, Georgia for the next two months, or because she just recorded a duet with ex-flame Nick Jonas?

Numerous sites and mags have confirmed the split, and a source tells Us Weekly, "They have been having trouble for a while. It's been hard for a long time since Miley has been working so much and traveling a lot." The source adds that Nick "was not the reason for the split, but they have been spending time together. Miley and Nick are working on a couple different projects together. Justin has been a little jealous of that."

However, we've also gotta wonder if the soon to be released duet between Nick and Miley was what really set things off between her and Justin! TWIST Magazine reports that the former couple did in fact record a "breakup song" together titled "Before the Storm," so perhaps interacting with her former sweetheart was another contributing factor?

Naturally, Justin and Miley have both been tweeting about the whole thing on their official Twitter pages, with Justin posting cryptic messages like, "Haven't been this miserable in a looong time.. I thought highschool was over," and "How many tears are in* there? They've gotta run out soon right." Meanwhile, little miss Miley has been tweeting everything from "life will go on. you will smile again.... we will smile again," to "why does saying good-bye hurt so much?"

Think these teenage (er, teen and twentysomething) lovers will end up together again? I mean, this break could just be a temporary thing while Miley shoots her movie, right?