Lily Allen is using Halloween to make another brutal dig after her breakup with David Harbour - this time, at his mistress! Perezcious readers know that the singer dropped a new album all about the actor's infidelity. On the record, there is a song called Madeline where Lily sings about David breaking the rules of their open marriage with this woman. We later found out that his mistress is Natalie Tippett, a costume designer who allegedly started an affair with the Stranger Things star while they worked on the 2021 Netflix film We Have A Ghost together. View this post on Instagram A post shared by NATALIE TIPPETT ???? (@natalie_tippett) Related: Lily Allen Quit Her OnlyFans After David Harbour Breakup! And in a savage move, Lily decided to dress up as his mistress... sort of! She didn't put on a blonde wig and whatnot! No, she alluded to the other woman by going as the beloved children's book character, Madeline! OMG! The Smile artist posted a video to TikTok of herself wearing a blue collared pea coat with a red necktie, a straw hat, Mary Jane shoes, and an orange wig while strutting her stuff and hitting a vape in a hallway. She captioned the post with a reference to her track: "Who IS Madeline though, actually?" Ch-ch-check it out (below): @lilyallen Who IS Madeline though, actually? #westendgirl #halloween ♬ Magnet - Cardi B This is iconic! LOLz! See more pictures of her look (below): (c) MEGA/WENN (c) MEGA/WENN Reactions, Perezcious readers? Share 'em in the comments! [Image via MEGA/WENN, Natalie Tippett/Instagram] The post Lily Allen Takes A Swipe At David Harbour's Mistress With 'Madeline' Halloween Costume! LOOK! appeared first on Perez Hilton.