King Richard's stars on geeking out when they met Venus and Serena Williams

“We were so excited that day! We were not expecting that at all,” said Sidney. Singleton agreed, saying, “That might have been one of the most fun days on set.”

Sidney says she’s proud to say that she can reach out to the sisters if she wants, telling us that, “It’s cool that we can call them friends. They were so supportive and everything, and that meant so much to us when we wanted to do justice by their story,” going on to call the pair “the funniest people ever.”

Both actors also gave us rave reviews about working with Smith. Sidney—who calls Smith “Mr. Will”—told us that, “He was so in character… Soon you will see how in character he was for Richard the entire time.” She also told us that she and Singleton, “learned so much from him, and it was so cool to see just how great of an actor he was,” saying, “He treated us like he was our actual dad.”

“One of the pieces of advice that he gave us was to be very careful and strategic about the roles that you choose as an actor or actress, as they can kind of define who you are throughout the course of your career,” said Singleton, continuing, “I’m definitely going to be using that throughout my career.”

King Richard hits theaters and HBO Max this Friday, November 19. You can read our review of the movie right here.