Lily Allen's ex David Harbour accused of 'cheating' on her for three years with a young costume designer

LOS ANGELES, CALIFORNIA: Speculation surrounding Lily Allen’s split from 'Stranger Things' star David Harbour has taken a dramatic turn.

A new claim has come to light, alleging the actor had been secretly seeing a younger costume designer for over three years, which the British pop star reportedly did not know about.

David Harbour accused of cheating on ex-wife Lily Allen

The couple, who officially separated in December after four years of marriage, had already been the subject of rumors, most notably, reports that Allen had found Harbour's profile on the celebrity dating app Raya.

Now, an insider has told Daily Mail that the 49-year-old American actor had been "cheating on Lily" with a costume designer he met on a film set.

According to the insider, they "weren’t very secretive about their relationship," with Harbour even paying for the woman to fly to Atlanta to "keep him company" on the set of 'Stranger Things'. 

‘David flew her to Atlanta while he shot Stranger Things to keep him company,’ they shared.

As if the affair allegations weren’t enough, Harbour is also rumored to have moved on with 27-year-old aspiring actress and model Ellie Fallon.

In February, sources claimed the pair were romantically linked following reports that they had taken a New Year’s trip to India together, as per Mirror.

Given that Ellie is 22 years his junior, the news has only fueled speculation about the circumstances surrounding Harbour and Allen's split.

Lily Allen opens up about struggles after split from David Harbour 

Lily Allen, 39, has been candid about the emotional toll the breakup has taken on her.

Earlier this year, she checked into a treatment center to cope with the trauma of the separation, later admitting she was still struggling to move on.

Following her treatment in January, she revealed that she had found "a good group of people" to support her while continuing to live in the US with her daughters, Ethel and Marnie, from her previous marriage to director Sam Cooper. 

As per Page Six, in a recent live recording of her 'Miss Me?' podcast on February 13 with best friend Miquita Oliver, Allen gave a raw and vulnerable insight into her current state. 

She said, "I'm finding it hard to be interested in anything. I'm really not in a good place. I know I've been talking about it for months, but I've been spiraling and spiraling and spiraling, and it's got out of control. I've tried."

Despite her challenges, Allen has emphasized that she’s working on her recovery.

During another podcast episode earlier this month, Allen appeared to take a subtle jab at her estranged husband while discussing her past relationships.

In an unfiltered moment, she admitted, "I don’t think there has been one person that has been remotely interested in my pleasure. I have actual d*** blindness. I can’t even picture, not even my ex-husband’s or boyfriend's. I can’t picture them at all. Apart from one as I have pictures of it on my phone."

She also touched on a deeper personal issue, referencing her own "daddy issues," which some speculate could be a nod to the 10-year age gap between her and Harbour.

However, she assured listeners she was working through it, stating, "I'm trying to stop that now."