Breaking up is hard to do, but for some couples, staying together is reportedly harder, especially if you are tween idols Justin Bieber and Selena Gomez. Although the year-long romance between the two may seem storybook, it couldn't be further from the truth, according to Radaronline.com. Sources say that the relationship is as rocky as they come. At the root of the problem? The Disney darling's penchant for jealousy. And it's apparently a two-way street. The insider tells Radaronline.com, "They both can be very jealous. Selena can be so dramatic about Justin's exes, who aren't even in her league! They both engage in really petty arguments, and it's killing their relationship." While 20-year-old Gomez may be the "Baby" singer's first love, she is supposedly more attracted to Bieber for the perks that come with being Bieber's girl. The insider says, "Justin's heart is with Selena because she's his first true love, but Selena is pretty much just riding out the relationship because she knows he's good for her image. Dating Justin is good for Selena's brand. Together they're a brand! Everyone in Selena's camp is aware of Justin's star power and is urging her to make it work with him." Of course, the source also points out that if Bieber's career fizzles out, the relationship will likely follow suit.