There's a surprising meaning behind the name Rose Byrne gave her second baby.

Australian actress Rose Byrne, 38, and her partner Bobby Cannavale welcomed their second son into the world four weeks ago.

Now Cannavale, 47, has revealed the meaning behind the name he and Byrne, 38, gave their new baby.

Cannavale told Entertainment Tonight they called him Rafa to honour his side of the family… and a certain world tennis champ.

“It’s going great. We’re a… little bit of lack of sleep in the house, but we’re doing well,” Cannavale began.

“I hadn’t given one of my children a Latin name yet, so I wanted to honor my mom’s side of the family.

“And, you know, Rafael Nadal had such a great year and we were constantly keeping up with him and watching all his matches so we were like, ‘How about Rafa? That goes well with Rocco.’ And that was it.”

Together Byrne and Cannavale also have a two-year-old son named Rocco, and Cannavale is also the father of a 22-year-old son named Jake, from his previous marriage.

We're sure Rafael Nadal is stoked to have a lil' Cannavale-Byrne named after him.

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