Selena Gomez Caught Justin Bieber in Bed With Kendall Jenner — Report

The Selena/Justin/Kendall love triangle just got more complicated — because Kendall and Justin actually started hooking up WHILE he was still dating Selena, a new report claims. And, to make matters worse, she caught them in action!

Justin Bieber, 21, and Kendall Jenner’s, 19, romantic relationship behind Selena Gomez’s, 22, back actually began long before they became friends with benefits earlier this year. It was actually after the 2014 Coachella festival that things started heating up…and a devastated Selena shockingly found out about what was going on firsthand, according to a new report!

Selena Gomez Caught Justin Bieber, Kendall Jenner In Bed — Report

Poor Selena! She totally found out in the worst way possible that her boyfriend and best friend had committed the ultimate betrayal, Life & Style reports.

“After the Coachella festival last April, when Selena and Justin were still a couple, Selena showed up at his house and walked in on him and Kendall in bed together, fooling around,” the mag’s insider claims. “Selena was heartbroken and literally freaked out.”

Selena Gomez & Kendall Jenner — Avoiding Each Other At Met Gala After Party?

Although the “I Want You To Know” singer eventually took Justin back for a few more months, the whole thing completely ruined her friendship with Kendall. “For months Selena sent her angry texts and insulted her,” the mag adds. “She was really mean to Kendall, but who could blame her? She thought she was her friend.”

But despite how furious Selena was that Kendall and Justin had gotten together, it didn’t stop them from rekindling the relationship this year. Although they never became an exclusive couple, the reality star and singer indulged in a secret relationship full of hot hookups for weeks. And to dig the knife in Selena’s back a little deeper, they attended Coachella together again this year! Ouch!

Justin Bieber Screams ‘Selena Looked Gorgeous’ Outside Met Gala — Watch

While Selena has mostly been able to avoid seeing Justin and Kendall together, all three of the young stars were in the same place at the same time at the Met Gala on May 4 — and this time it was Selena that Justin had his eye on!

“Yo, Selena looked gorgeous at the Met Ball!” he screamed out the window of his car, as a videographer recorded the entire thing.

In fact, HollywoodLife.com has EXCLUSIVELY learned that Justin spent the entire night pouring out compliments about his ex. “Justin couldn’t take his eyes off Selena at the Met Ball. He said that she looked like a princess and was giving her all sorts of compliments,” an insider told HollywoodLife.com EXCLUSIVELY. “He played right into her aloofness, which made him want her even more. It was perfect because this is exactly what Selena wanted.”

Kendall Jenner & Justin Bieber: How Kris Jenner Pushed Romance

No worries, though — Kendall appeared to be having a great time herself, enjoying the night with friends like Hailey Baldwin and Gigi Hadid, as well as her sister, Kylie Jenner.

Okay, HollywoodLifers, we need your thoughts! What do you think of Selena’s reaction to allegedly walking in on Kendall & Justin? Do you think there’s ever a way these three can work out a friendship?

— Alyssa Norwin