Ever Wondered How Kristin And Justin's Love Affair Ended?

On tonight's episode of "The Hills," we saw Justin Bobby come face to face with his ex, Kristin (who don't forget, "did things" to him that Audrina never could), for the first time since last season's finale. Back then, we were really pulling for the noncommittal couple to make it work and actually felt optimistic about their chances of riding off into the sunset wearing matching glittery helmets. Unfortunately, something must've gone awry during the break in filming to drive these two apart, which makes us doubly sad since they really looked adorbs tonight in those complementary cutoff vests.

While we were happy to see that the two natural-born players are still on good terms and want the best for each other (Kristin really seems to think JB and 'Drina should give it another whirl!), a nagging elephant in the room question remains: Just why did they call it quits? Below are a few possible absurd theories we put together for our own entertainment pleasure -- take a look, then share with us how YOU think the relationship ended.

Another Man?

Justin met Brody for brunch one day and suddenly realized that the Brodester was not actually sporting a new trend (the men's half-shirt) but his girlfriend Kristin's favorite nightshirt.

Another Woman?

Ever since Vegas, K-Cav couldn't stop thinking about that kiss with Stacie the Bartender and decided she wanted to try something new and different. Ultimately, Stacie broke things off after just three short weeks when she found a crack pipe in her lover's purse. (At least, that's what Lo Bosworth's been leading us to believe.)

Another Gender?

Stephen Colletti sabotaged the relationship by spreading rumors that Kristin was born a dude. (Hey, we knew she had balls!)