Selena Gomez feels "betrayed" by Justin Bieber and Kendall Jenner.

Justin Bieber

Justin Bieber

The 'Heart Wants What It Wants' hitmaker is said to have been left feeling as though she's been "stabbed in the back" after pictures surfaced of Justin and the 'Keeping Up With The Kardashians' star enjoying the Coachella festival together.

An insider said: "Those Instagram photos of Justin and Kendall at Coachella just confirm what Selena thought all along... that Justin was cheating on her with Kendall. And it all started at last year's Coachella.

"Both Justin and Kendall denied any type of romance at the time, but Selena always had her doubts.

"It stings. Seeing the recent pictures of Justin and Kendall together is like a stab in the back all over again. It's not that Selena wants to be back with Justin. It's more of a betrayal thing. She feels betrayed by Justin and Kendall."

But Selena reportedly could have been there with Justin if she had accepted his invite to the music festival.

The 'Boyfriend' hitmaker reportedly asked his ex-girlfriend along to the event in an attempt to win her back.

A source shared to "Selena said that Justin reached out to her in Atlanta and congratulated her on almost wrapping production. He told her she should come join them at Coachella.

"This was his way of saying, 'I miss you', and 'I am not dating anyone, at least not seriously'. It was his way of breaking the ice."