After news broke that the 'Black Widow' actress has given birth to their first child together, the 'Saturday Night Live' star takes to Instagram to reveal the baby's name.

• Aug 19, 2021

AceShowbiz - Scarlett Johansson and Colin Jost are already on diaper duty. Just days after the comedian confirmed that they're expecting their first child together, it has been revealed that they have welcomed a son.

The news broke on Wednesday, August 18 and was confirmed by the actress' rep Marcel Pariseau to PEOPLE. Later on the same day, the new father took to Instagram to reveal the name they have given to the newborn.

"Ok Ok we had a baby. His name is Cosmo," Colin wrote in an Instagram post over a plain black background. He added, "We love him very much." He also asked for privacy during this time and jokingly directed all further inquiries to his "Saturday Night Live" co-star Michael Che.

"Privacy would be greatly appreciated," the 39-year-old added on the next slide. "For all inquires please contact our publicist @chethinks." He added some playful hashtags in the caption, "#wegotawaywithitforalongtime," "#nokidspolicy" and "#we'regoingtodisneyworld".

While Colin didn't give away many details of the baby and delivery process, it's apparently been a while since he and Scarlett welcomed their son. In a Deadline article about the "Black Widow" lawsuit, it's said that court documents stated the 36-year-old actress was "in the hospital in labor" as Disney responded to her lawsuit, which she filed while "heavily pregnant."

Scarlett is suing Disney over the simultaneous release of her movie in theaters and on Disney+, claiming it was a breach of contract. She alleged that the release on Disney+ impacted her salary she could earn from the film's ticket sales in cinemas. Disney responded to her filing on July 29, claiming there was "no merit" to her stance.

The news of their baby's arrival comes just days after Colin confirmed the pregnancy. "We're having a baby, it's exciting," so he told the audience during a stand-up show at the Ridgefield Playhouse in Connecticut over the weekend.

While the newborn baby boy is the first child for Colin, his actress wife is already a mother to a daughter named Rose Dorothy Dauriac, whom she shares with her ex-husband Romain Dauriac, the owner of an advertising agency. Scarlett and Colin tied the knot in October 2020 at their New York home.