Fans are desperate for Justin Bieber and Selena Gomez to get back together — but Selena's mother is determined to make sure that never happens.

Selena, 24, recently completed a short stint in rehab, and sources reveal exclusively to Life & Style that her mom, Mandy, has reached out to Justin, 22, to warn him to leave her daughter alone!

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"Her family fees that no one has ever gotten under her skin like Justin and, ultimately, he affected her in a deeply negative way," a source explains. "Mandy really believes that Selena will be able to heal faster without him."

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Last month, Life & Style reported that the brunette beauty's relationship with the "Sorry" singer prompted her rehab stay.

"While Selena does suffer from lupus and other health issues, that's not the reason she went to rehab," an insider explained. "Her biggest addiction is Justin."

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The source continued, "She became a different person around him. She was extremely jealous and possessive and felt like she had to keep up with him to keep him. So she would drink and smoke, and then she got into weed and partying."

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The "Hands to Myself" singer made her first red carpet appearance post-rehab at the American Music Awards, and opened up about her state-of-mind in a powerful speech.

"In 2014, this stage was actually the first time that I was authentically, one hundred percent honest with all of you," Selena said. "I think it's safe to say that most of you know a lot of my life, whether I like it or not, and I had to stop, 'cause I had everything and I was absolutely broken inside. And I kept it all together enough to where I would never let you down, but I kept it too much together to where I let myself down."

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However, it looks like things are turning around for the pop star — who was recently spotted kissing The Weeknd, who is fresh off a breakup with model Bella Hadid.

For a look back at Jelena in happier times, click through the gallery below!