"People run up to him and they literally will put their phone two inches from his face. He can't handle it," says a Bieber source
Credit: Jeff Kravitz/FilmMagic

After months of erratic behavior from Justin Bieber, things appeared to reach a head when the star was involved in an altercation last week in Cleveland.

Now, a source tells PEOPLE exclusively the drama – which involved Bieber taking a swing at a man – came as no surprise to those close to the singer.

“In the week leading up to the fight, you could tell he was going to snap,” says the source. “It was like a bottle had been shaken.”

It appears the Cleveland incident was sparked when “something negative” was said to Bieber by a heckler, adds the source. “People run up to him and they literally will put their phone two inches from his face. There’s no filter with these fans. They spring up to him and just throw their phone to the point where they almost smack him.”

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Earlier this year, the “Sorry” singer disappointed his fans when he announced he was canceling all his Purpose Tour meet-and-greets because “I end up so drained and unhappy.”

“He can’t handle or tolerate it,” says the source about the excessive attention Bieber receives when he’s out and about. “It has him on edge all the time.”

After the fight, the star addressed the incident on Instagram, posting a video on Instagram where he and his pal Micah Cravalho joked about picking fights. “Is that a fighting video? Dude, fighting’s not cool,” he said in the video. Retorted Cravalho: “I know, that’s why you don’t take on 6’5″ guys.”

Though the last few months have been rocky for Bieber, there is one aspect of his life that has been going much more smoothly: his relationship with his mom Pattie Mallette.

In an interview with Billboard last year, he admitted his relationship with his mom was “pretty non existing.” But earlier this month, he posted a photo of himself with Mallette getting pedicures, and the source adds that mom and son are “doing much better” now. “They’ve been working on their relationship,” says the source.