When your best friend is a princess, everyone wants to know about her. When it comes to Serena Williams, however, she knows how to keep a secret. The tennis champion has remained close-lipped about her relationship with Duchess Meghan Markle and has become a master at dodging questions about her.

“Don’t know what you’re talkin’ about, don’t know nothin’ about that,” she told Naomi Campbell about Markle on “No Filter With Naomi” on Monday, according to People.

When Campbell continued pushing Williams to open up about the Markle’s recent move to Los Angeles, Williams once again dodged the question.

“Never seen it, never heard of her, don’t know her,” she said.

Williams and Markle first met in 2010 at a Super Bowl party, eight years before Markle married Prince Harry and became the Duchess of Sussex we know her as today, The Sun reported. At the time, Markle was a young Hollywood actress and Williams was the No. 1 tennis player in the world, according to The New York Times.

From there, their friendship blossomed into one of strength and support, often each woman relying on the other to deal with media critics.

“We were actually just texting each other this morning,” Williams said in a 2018 interview on “The Sunday Project,” according to The Independent. “We have known each other for a long time, but we really are relying on each other a lot recently.”

It’s possible Williams can even be credited for introducing Prince Harry and Markle. The Duke and Duchess of Sussex met in London in July 2016, right around the same time the Wimbledon Championships were taking place. Once Markle began dating Prince Harry and faced media scrutiny, she reached out to none other than her old pal, Williams.

“I told her, ‘You’ve got to be who you are, Meghan. You can’t hide,’” Williams told Vanity Fair in 2017.

The two women have continuously shown support for one another throughout their careers with Markle attending many of Williams’s tennis tournaments and Williams politely declining to discuss Markle’s personal life. William also attended Markle’s wedding to Prince Harry in May 2018.

Meghan Markle Serena Williams
Meghan Markle is pictured on Jan. 30, 2019 in London and Serena Williams is pictured on Dec. 2, 2018 in Los Angeles. Chris Jackson/Getty Images/Presley Ann/Getty Images for Beautycon