Lily Allen calls Stranger Things star David Harbour 'mine' as she makes their relationship Instagram official... after revealing she's leaving the UK with him until Brexit By Kate Thomas for MailOnline Published: 16:09 BST, 14 October 2019 | Updated: 16:11 BST, 14 October 2019 Viewcomments They've been linked since August when they were spotted on a theatre date in London's West End. And Lily Allen confirmed she was officially dating David Harbour, 44, on Monday, by sharing a picture of The Stranger Things star's bulging biceps during his Saturday Night Live hosting gig, captioning the image 'Mine'. The 34-year-old star's loved up social media posts came just one day after the unlikely duo were pictured kissing on the street in New York City. It's official: Lily Allen, 34, confirmed she was dating David Harbour, 44, on Monday, by sharing a picture of The Stranger Things star and captioning it 'Mine' Lily and David had been seen ogether a number of times over the last few weeks, including a date night at the Hughie Fury vs Alexander Povetkin boxing match at London's O2. The Smile hitmaker now seems to have made things social media official, signalling they are exclusively dating. She had supported David during his SNL hosting debut on Saturday night and was even spotted leaving the show alongside the actor's family. The London-based star also hinted she was going to stay with David in America until the Brexit deadline of October 31 when the UK is due to leave the European Union. Sharing a number of selfies of herself, the singer wrote: 'Leaving UK till after Brexit. Good Luck Kids. Also what’s the most annoying engagement baiting question caption you’ve read ? LMK in the comments'. His number one fan: She uploaded a screengrab of David's bulging biceps from his Saturday Night Live hosting gig over the weekend By his side: She had supported David during his SNL hosting debut on Saturday night and was even spotted leaving the show alongside the actor's family David is believed to have split from Fantastic Beasts star Alison Sudol earlier this year following a long-term romance. Lily separated from husband Sam Cooper in 2015 after about four years marriage, finalising their divorce in 2018. They share joint custody of their two daughters Ethel, seven, and Marnie, six, and remain 'really friendly' to this day. During an interview on Loose Women back in 2018, she said: '[Our custody agreement] wasn't really something we discussed, we're both really friendly, our kids go to school equidistant between our houses, so it works.' Joining him in the USA: The London-based star also hinted she was going to stay with David in America until the Brexit deadline Amid their separation, the songstress dated grime DJ MC Meridian Dan, real name Daniel Lawrence London. The pair first started dating three years ago and the Smile hitmaker told How To Fail podcast host Elizabeth Day that she and Dan had broken up in December 2018. She said at the time: 'I’m single, for the first time since I was about 15. I’ve just come back from a tour in America, which is where I was when things went wrong with Sam, and the same thing happened in my current relationship. 'I mean, I didn’t take lots of drugs and have lots of sex with other people. I just became very lost.' Ex-husband: Lily separated from husband Sam Cooper in 2015 after about four years marriage, finalising their divorce in 2018 (pictured in June 2014) Split: David is believed to have split from Fantastic Beasts star Alison Sudol earlier this year following a long-term romance (pictured in 2018) Share or comment on this article: All rights reserved for this news site (fashion) and under his responsibility