Serena Williams didn't tell daughter about pregnancy until 2023 Met Gala

Serena Williams held off telling her daughter about her pregnancy for a good reason.

In a video posted to her newly launched YouTube channel this week, the tennis star discussed why she decided to announce that she and her husband Alexis Ohanian are expecting their second child at the 2023 Met Gala earlier this month.

Serena revealed to viewers that she didn't tell her five-year-old daughter Olympia that she would become a big sister until the day of the annual fashion event.

"Olympia does not know right now that I am pregnant, so the big reveal will be at the Met, and then before we leave, I'll tell Olympia," the sportswoman shared in the footage. "The reason I haven't told her is because she can't keep a secret."

In August 2022, Serena announced that she was retiring from tennis and planned to focus on her family.

She wrote in a Vogue essay, "In the last year, Alexis and I have been trying to have another child, and we recently got some information from my doctor that put my mind at ease and made me feel that whenever we're ready, we can add to our family. I definitely don't want to be pregnant again as an athlete.

"I need to be two feet into tennis or two feet out."

Serena, 41, married Reddit co-founder Alexis in 2017.