Megan Fox, fiance Machine Gun Kelly working on their relationship

A source tells People magazine that Megan Fox and Machine Gun Kelly are improving their marriage.

A source close to the pair claims that they are "in therapy" after the actress hinted at a possible split last month. Nevertheless, Fox, 36, is "having a hard time trusting" MGK, 32, as a result of reports of his adultery, which she has subsequently disputed.

"This is really boiling down to not working," the source says. "There have been points where they haven't been speaking, it's been that bad."

Another insider offers that they are in contact and "still working on their issues," adding: "Only time will tell if they get back together properly, but it looks pretty unlikely right now."

The insider mentions that the couple has "always had kind of a tumultuous relationship," which has "never been easy, it's always been very up and down."

"Megan was thrilled when they got engaged, though. She really loves him," the insider continues. "She was never one to casually date, so she put her whole heart into their relationship. She isn't happy now, though. She took her engagement ring off a while ago, and it's not back on."

Fox made a notable appearance at the Vanity Fair Oscars afterparty this month without the engagement band on her finger.

Last month, Fox fully canceled her Instagram account, hinting at a possible breakup with her musician fiancé by removing any references to him from the site. Her move seemed to indicate that the couple had struck a rocky patch.