Updated

Justin Bieber is firing back at a TV host who insulted his Coachella performance with Ariana Grande on Sunday.

Morgan Stewart, host of E!’s “Nightly Pop,” reportedly accused the 25-year-old singer of lip-synching “Sorry” on Sunday during his first performance in 2 years.

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“I did not realize it was gonna be that bad,” Stewart said, according to Us Weekly.

Bieber fired back at the host on social media Wednesday in a series of tweets, defending the appearance of his lip-synching and reprimanding her for “tearing people down.”

In his first tweet, Bieber accused her of being a bully, saying: “@Morgan_Stewart just saw a video of you ripping me to shreds saying I was lip-syncing. They played the song and i just sang overtop of it.. regardless why spend your time tearing people down. It’s People like you that are bullies at school that are making kids suicidal.”

He then continued to challenge her comments, suggesting her time would be better served “building people up.” He also reminded her it was his first performance in 2 years and that he “sang to backtrack like most cameos do.”

“And rather than try and make people feel accepted and loved you find things to pick apart like the world isn’t full of that already.. we can find something negative to say about anything or anyone,” he added in the thread.

The “Baby” singer concluded: “When are we gonna be the kind of people that find joy in adding value to one another and not tearing each other apart.”

Fox News requests for comment from E! News and Stewart were not immediately returned.

JUSTIN BIEBER JOINS ARIANA GRANDE AT COACHELLA FOR HIS FIRST PUBLIC PERFORMANCE IN 2 YEARS

Bieber joined Ariana Grande for a surprise duet at Coachella on Sunday.

“We thought it might be fun to do something for you guys,” Grande said before Bieber got on stage to perform the 2015 hit song, People reported.

Justin Bieber joined Ariana Grande for a surprise duet at Coachella on Sunday, marking his first onstage performance in two years. (Getty Images)

“I haven’t been on stage in like two years. I came out here I had no idea I was going to be on stage tonight,” Bieber told the Coachella crowd. “So anyways this is my first time on stage in two years. I had to get my groove back, my swag back, you know what I’m saying? So, thank you so much, Coachella. Thank you so much, Ariana Grande. We love you so much, man. Thank you so much.”

Bieber last took the stage in July 2017 for his “Purpose” world tour, but he abruptly canceled the final 14 shows “after careful consideration.” He told Vogue in February that he decided to stop touring because he got “really depressed.”

Fox News’ Katherine Lam contributed to this report.