Lily Allen & David Harbor's Rumored Mistress Are Locked In A Nasty Feud

Lily Allen may have used Dakota Johnson as the other woman while performing her hit, scandal-laden song "Madeline" on "Saturday Night Live" this month, but now the alleged real Madeline is speaking out. Hollywood costume designer Natalie Tippett took to her Instagram Story on December 15, 2025, to address what is being said about her alleged relationship with Allen's estranged husband, David Harbour, after rumors ignited that the singer's song is about her. "I did not have a three-year affair with anyone," Tippett began (via Page Six). "I'm unsure why this person wants so badly to pit people against me or create this narrative that we both know is false based on the actual messages that I have saved between us. The same ones that have now been referenced in a song without my consent."

Allen's "Madeline" — a track on her album "West End Girl," which was released in October — describes a brutal betrayal in a relationship, wherein one partner breaks the rules of their open relationship and sleeps with Madeline, whom Allen describes as "not a stranger" (supposedly revealing the truth about Harbour's marriage to Allen). Interspersed in the song are messages from Madeline, which Tippett has now seemingly confirmed to be based on real conversations between herself and the Grammy nominee. While Allen told The Times that Madeline was "fictional," she confirmed that the titular character was based on a real person or a "construct" of people.

In the same month of the album's release, Natalie Tippett spoke to the Daily Mail, exposing herself as Madeline and discussing her relationship with the "Stranger Things" actor. According to the outlet, Tippett and David Harbour — who has been in the headlines for more than one shady rumor this year — met on the set of Netflix's 2021 film, "We Have a Ghost," and had an adulterous relationship during and after filming. At the time of her interview with the Daily Mail, Tippett reportedly verified that Lily Allen was quoting their text chain, but said, "I just don't feel comfortable talking about it at the moment."

After immense backlash and harassment online, Tippett seemingly decided it was time to address the conflict between herself and Allen. "I'm aware of the repercussions speaking out on this may cause, but I can't imagine anything worse than what's already been said, as well as having to watch someone profit off of painful lies ... so at this point at least I've said my truth and on my own terms," Tippett wrote on her Instagram Story, per Page Six. She also asked her followers to be kinder, as she had been receiving death threats via social media. She reminded her Story viewers, despite her role in Allen's song, "I am a human being not a character someone created."