Tuva Novotny and the 46-year-old actor welcomed a baby together.
ET found out Alexander was gifted a stuffed animal for his kid by a fan at the Succession premiere in New York City on Monday (March 20).
"I got this on the red carpet," he said. "Thank you so much."
Tuva confirmed her pregnancy at Stockholm's Elle Gala in April last year, before she and Alexander were seen strolling together in NYC.
During a nighttime stroll with their newborn in November, the couple was also spotted.
On Sunday, March 26 on HBO, you can catch Alexander in Succession's final season.
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