A source said: "The liking of the Instagram is just a shot at Zedd because he is all about his album and work and not focusing all of his attention on her. Zedd has realised he really hates these childish games she is playing and is really getting over her.
"Zedd doesn't want to be a tabloid guy, he wants to be an artist and the games Selena plays puts her in the news all the time. He has given her an ultimatum, lose Justin or lose him."
It may be hard for Selena to let go of her former flame as an insider recently claimed she was feeling "betrayed" by the 'Baby' hitmaker after he was seen with Kendall Jenner at Coachella music festival.
Another source added to HollywoodLife.com: "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."