Their romance was allegedly rumoured over the summer, but it sounded so utterly random that we found it hard to believe.
The pair were papped in New York the other day as they walked through Chinatown, and they were not shy about their PDAs.
Harbour hosted SNL on Saturday night, and apparently the LDNer was in the audience to support him. Allen split from her boyfriend of three years, Meridian Dan, last Christmas. Harbour's most recent relationship was with actress Alison Sudol, which ended earlier this year.
Allen confirmed the relationship on her Instagram story, sharing a screengrab of Harbour's bicep from SNL and captioning it 'mine'.
There's a multitude of photos doing the rounds on social media that show them pretty loved-up, some of which you can see below... as well as the reaction to their relationship.
G'luck to them, etc...
Fica esperta, Joyce, porque o Hopper tá com uma nova pretendente na área! kkkkk O astro de #StrangerThings David Harbour está assumidíssimo com @LilyAllen! O casal passeou de mãos dadas e trocou o maior beijão nas ruas de NY... https://t.co/fMVnawCYPA (Fotos: BrosNYC / BACKGRID) pic.twitter.com/DlhzCeI3La
— Hugo Gloss (@HugoGloss) October 14, 2019
— Sara Williams (@fashionsarany) October 15, 2019
david harbour and lily allen are dating what the fuck
— jasmine (@rihreeves) October 15, 2019
Halloween couples costume idea: David harbour and lily Allen
— kaj-mahal🤪 (@kajal_btw) October 15, 2019
David Harbour and Lily Allen are a couple ... I just ... pic.twitter.com/Y2nW1wO7iu
— Lauren Anne #Replayer F500 (@LozzimusPrime) October 14, 2019
did anyone know that david harbour and lily allen were dating or was i just supposed to find out myself????
— liv // charlwave (@Liv_October) October 14, 2019