Arnold Schwarzenegger Marks Joseph Baena's Birthday With a Father-Son Gym Session

The Terminator actor shared a photo of himself and son on Instagram, writing a sweet note: “Happy birthday Joseph! You’re a fantastic son and a great training partner. You get stronger and smarter every year and I’m so proud of you. I love you."

Arnold Schwarzenegger is celebrating one of his sons birthday in his domain — the gym.

The Terminator actor, 70, shared a photo of himself and son Joseph Baena, 20, on Instagram Monday writing a sweet note.

“Happy birthday Joseph! You’re a fantastic son and a great training partner. You get stronger and smarter every year and I’m so proud of you. I love you,” the actor wrote in the caption.

The former governor of California stood proudly by Joseph as the latter worked out, pointing at him and grinning at the camera.

The duo often work out together. About five days ago, Schwarzenegger wished his third son, Christopher, a happy birthday as well, sharing a touching photo of his son during his early childhood kissing his dad.

The two enjoyed Joseph’s birthday last year with a trip to Oktoberfest in Munich, Germany, where the father and son enjoyed the wide selection of beers at the festival.

Joseph is the son of Mildred Baena, Schwarzenegger’s former housekeeper who he had an affair with when married to ex-wife Maria Shriver.

The actor also has four children with Shriver: Katherine, 27, Christina, 26, Patrick, 24, and Christopher, 20.