Despite the love they shared and their best efforts to preserve it, the relationship between Justin Bieber and Selena Gomez just isn't working. Sigh times 10.

RadarOnline is reporting that sources say the couple valiantly attempted to keep the romance alive, but it just isn't going as planned. Looks like the Biebs' lyric, "If I was your boyfriend, I'd never let you go," didn't translate in real life.

"Justin and Selena were together for a long time. They love each other and will always care about each other, but it just isn't working," the source said.

The latest update is that the couple split after a fight in Mexico before New Year's Eve, with Gomez hightailing it out of there on Dec. 30. There were other rumors that his possible pot smoking was the last straw for the singer/actress.

The insider continued, "This might really be it for the two of them. They're over going back and forth and all the fighting and reconciling. They're finally realizing that no matter how much they try to make it work, it won't right now."

Despite the warm, sunny locale, things were frosty between the once red-hot couple. Brrrr. "Their time in Mexico was much of the same for them; constant arguments and bickering," the insider claimed. "So they ended it. Selena is Justin's first love and he's still young enough that he desperately tries to make it work. But Selena is mature enough to just know when to end it and be realistic that it isn't working."

While the Biebs was dealing with paparazzi issues -- the death of a paparazzo who was tailing him for months and who died tried to obtain a photo of him in a situation where he wasn't even present and those blunt photos -- Gomez moved forward. "Selena didn't wallow in their breakup. She went out New Year's Eve and had fun with her friends and did her thing," the source said.

While "they're just having trouble saying goodbye," the source doesn't see another last ditch effort or a reunion.

Jelena fans, how crushed are you over this news? We know the haters are probably happy, but it's a bummer anytime a couple as cute as this can't get their you-know-what together.

Watch the Justin Bieber 'Boyfriend' Video