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Justin Bieber and Selena Gomez have once again proved that stars are just like us -- if we were all still in high school. Their romantic foibles are back in the headlines, this time with a healthy dose of jealousy and revenge tossed in.

Let's start with the curious case of the Instagram unfriending. Last week, Selena, 21, reportedly stopped following the Jenner sisters, a move that came shortly after they all hung out together at the Coachella Music Festival.

Gomez apparently believed Kendall, 18, and Kylie, 16, were a negative influence; their camp sniped that the popster is the toxic one. But it appears Selena's dysfunctional on-off romance with the Biebs, 20, may have been at the heart of the rift.

"Selena felt Kylie was flirting with Justin," a source tells Us Weekly, with another adding, "It got messy. Selena said the Jenner girls were flirting with Justin and his crew. She was pissed and overreacted."

An insider echoes the flirting factor to E! News, claiming Gomez got "a bit jealous." According to Radar Online, some "shocking texts" were also involved.

But now, it seems, all is well.

"Selena has no issues with the Jenner girls," maintains an Us spy. "They had an issue, but they have cleared it up. She has always liked the Jenner girls. They had been fans of Selena since they were young."

But is Bieber flaunting the Jenner connection to his sometime flame, who was spotted last weekend with Orlando Bloom?

On Monday, Kendall met up with Justin at a New York studio, and soon after they hit Nobu for sushi (tagging along: her pal, Hailey Baldwin, daughter of Stephen).

Adding to the trying-to-make-her-jealous theory: A day later, Justin Instagrammed a sultry photo of model Ashley Moore, whom he was linked to last year (and who bears a slight resemblance to Gomez). "Super cute," he wrote. "Proud of you."

Probably not coincidentally, these actions came just days after Selena was snapped with Bloom at Chelsea Handler's stand-up show in Los Angeles, sparking talk of an age-mismatched hookup.

But a source assures E! News that they're "not dating" and were at the show with "a bunch of people."

And in a final bit of high school news, Radar claims Selena's falling out with former BFF Taylor Swift was a mutual decision, although Selena's side gets in a pitch-perfect put-down.

"Taylor hasn't talked to Selena since she started hanging out with Justin and the Jenner girls," says a source. "Selena was also so damn bored with Taylor. She didn't want to bake cookies or paint anymore. She was just so done with it all."

Oooh, a cookie burn. That's the worst kind of burn.


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