Justin Bieber and Selena Gomez break up again!

Selena Gomez may be too hot for Justin Bieber to handle. The on-and-off couple had a huge blowout during their holiday getaway to Mexico, and they haven't seen each other since, The New York Daily News reports.
"They keep breaking up and getting back together," an insider said of the 18-year-old pop superstar and his 20-year-old girlfriend. "It's an on-again, off-again relationship. It's probably not correct to characterize this as a final breakup."

So what's driving them apart? A source says that sexy Selena has been "partying" without the Biebs, and "it drives him crazy." Jealous much?
But Bieber and his "Baby" aren't the only celebs who can't seem to stay away from each other. Against all odds, Robert Pattinson got back together with his "Twilight" co-star Kristen Stewart after her "momentary indiscretion" with her married "Snow White" director. Rihanna posted pictures of herself in bed with Chris Brown on New Year's Day — even though he pleaded guilty to assaulting her in 2009. And Hugh Hefner tied the knot with his 60-years-younger girlfriend Crystal Harris on New Year's Eve . . . after she called off their wedding in 2011.

Justin Bieber and Selena Gomez split upagain over the holidays, after a romantic vacation in Mexico turned sour. "Their time in Mexico was much of the same for them; constant arguments and bickering," a friend told Radar. "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."

Unlike last time they split, though, it looks like Biebs wasn't mourning and begging for her to take him back. He was photographed at a party in an Orange County hotel room this week... smoking a blunt, as you can see from the TMZ photo above. Sources tell the site that Bieber's buddy Lil Twist (the rapper who was driving Bieber's car when a paparazzo was killed last week) was rolling the blunts, and that the room was full of marijuana smoke.

So much for Biebs' clean-cut image?

Word is, most of the scintillating conversation at the party was about how tired Bieber was after staying up too late, and about getting their hands on some fast food. (Fascinating stuff, really.) A girl who is not Gomez spent the night in Biebs' hotel room.