American Scarlett Johansson and her compatriot Colin Jost have made their relationship red-carpet official.

The Black Widow actress, 33, and Saturday Night Live star, 35, were arm-in-arm on Monday night at her Avengers: Infinity War world premiere in Hollywood.

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Johansson joked on the American television programme Entertainment Tonight that her first red-carpet walk with Jost “was all right, not bad”.

She added: “I’m just excited to share this experience with him because I’m so excited to see the film. I haven’t seen it before!”

Johansson also appeared on The Ellen DeGeneres Show on Monday, where she was asked to pick between Jost and his Weekend Update co-anchor, Michael Che.

“I guess I’m a Colin fan, I’d have to say,” she grinned.

The actress, who stars in the newest film in the Marvel Cinematic Universe, met Jost when she first hosted Saturday Night Live in 2006. At the time, Jost was a new writer on the hit US show.

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However, the couple wasn’t romantically linked until last year, after Johansson finalised her divorce from French journalist Romain Dauriac following two years of marriage.

Johansson and Dauriac have a three-year-old daughter, Rose, together.

The actress was previously married to US actor Ryan Reynolds.

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