Chris Pratt makes Katherine Schwarzenegger relationship social media official

This browser does not support the video element.

It was one of the worst kept Hollywood relationship secrets, but now actor Chris Pratt has made it Instagram-official. He is dating Katherine Schwarzenegger, daughter of actor and former governor, Arnold Schwarzenegger and his ex-wife, Maria Shriver.

Pratt, 39, posted photos and a birthday message for Katherine Schwarzenegger. While the couple has been in other family members' social media posts, this is one of the first Instagram collage posts of his girlfriend made by the Marvel and "Jurassic World" actor, USA Today reported.

Pratt and his wife of eight years, Anna Faris, separated in 2017, CNN reported. They had a son, Jack.

He made the post in honor of Schwarzenegger’s 29th birthday.

She runs a lifestyle blog and has written a book, "Rock What You Got," USA Today reported.

On Tuesday night, Pratt was photographed with Katherine's younger brother Patrick at the LA Clippers game, People reported.

In this handout from Disney Resorts, Chris Pratt narrates the story of Christmas during Disneyland's annual Candlelight Processional on December 01, 2018 at Disneyland in Anaheim, California.  (Joshua Sudock/Disney Resorts via Getty Images)