"With Amber, there has been nonstop drama," the source claims. "[Johnny and Amber] are just not good together. They had lots of problems before they got married, and should have never gotten married. Their personalities are just not compatible."
The source alleges that Heard exacerbates Depp's "jealousy issues," claiming that the actor is "very insecure when it comes to Amber."
In the past week, Heard has levied domestic violence allegations against the 52-year-old actor in court documents. She was granted a temporary restraining order against Depp on Friday, after alleging that the star abused her throughout their four-year relationship and 15-month marriage.
Heard, 30, claimed in court documents that Depp hit her with a cell phone and pulled her hair during an altercation on May 21, and she submitted to the court photos of herself with what appears to be a bruise on her right eye. An LAPD spokesperson told WHO, however, that officers responded to a 911 call but determined there was "no evidence of any crime" on the scene.
In response to Heard's restraining order request, Depp's divorce attorney Laura Wasser said in court documents that Heard is "attempting to secure a premature financial resolution by alleging abuse."
Amid the shocking allegations, the insider tells WHO that ending the marriage is a positive step for both parties.
"After the recent drama, people close to Johnny feel a divorce is the best outcome," the insider tells WHO. "Johnny and Amber should not be married."
Depp took the stage in Germany with his band the Hollywood Vampires on Sunday, performing alongside Alice Cooper and Joe Perry. Earlier in the week, Depp performed at the Rock in Rio festival in Lisbon, Portugal, with the band, and seemed "absolutely fine," according to a concertgoer.
"He played a really good gig. It was like the events of the week hadn't played a part at all," the witness told WHO.
The actor's family has come to his defense against Heard, with daughter Lily-Rose Depp, 17, calling him the "sweetest, most loving person I know" on Instagram.
Her mother, Depp's ex-partner of 14 years Vanessa Paradis, also reportedly wrote a letter supporting the actor.
In the handwritten note, obtained by TMZ, Paradis allegedly wrote that "these recent allegations being made are outrageous."