The Stranger Things star, 44, and the British singer, 34, were photographed locking lips as they walked through the streets of New York City on Sunday to grab lunch together.
Harbour wore large glasses, a light jacket and gray pants for the daytime outing, while Allen opted for a gray sweater, blue jeans and a purple purse.
In a second photo, the actor snuck in a kiss on his rumored girlfriend’s cheek.
Harbour wore a camouflage jacket, blue shirt and black pants. Allen opted for a black coat while she carried a Chanel purse. Harbour’s father, Kenneth, was also photographed with the pair heading to the party.
Allen shared photos from Harbour’s SNL sketch parodying a SoulCycle class, during which the host wore a sleeveless shirt and showed off his muscular arms. In a zoomed-in photo of Harbour’s bicep, Allen captioned her image: “Mine.”
Harbour was previously spotted with Allen in August while he was filming Black Widow in London. The two attended the performance of The Lehman Trilogy at the Piccadilly Theater and then dined at a restaurant, according to E! News.
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“I’ve always had a boyfriend. I don’t at the moment. I’m single for the first time since I was about 15,” Allen said on the How to Fail with Elizabeth Day podcast.
Allen was previously married to builder and decorator Sam Cooper, 41. They married in 2011 and announced their split in 2016 before finalizing their divorce last June. Allen and Cooper share two daughters: Ethel, 7, and Marnie, 6.