Arnold Schwarzenegger was sharing the online love after two of his sons reached a major milestone within the same week.
On Sept. 27, Christopher Schwarzenegger turned 21, prompting the actor to share an adorable throwback image of the little guy on his dad's shoulders.
"Happy birthday Christopher!," Arnold captioned the image. "You're a better student than I ever was, and you have the biggest heart I've ever seen. I'm so proud of you and I love you."
Less than a week later, on Oct. 2, Arnold's son Joseph Baena also turned 21. Like he did with Christopher, Arnold took to Instagram to praise his son, sharing a recent image of the father and son clutching their fists outside the gym.
"Happy birthday Joseph! It's been fantastic to watch you pump up your muscles and your mind this year and I can't wait to see what's next," he wrote of the image in which both men look physically fit. "I'm proud of you and I love you!"
Joseph also got in on the birthday action on Oct. 3, sharing several images from his big day.
"Birthday mems," he wrote of the images.
Joseph and Arnold have become close over the years ever since it became publicly known that the action star secretly fathered Joe with Mildred Baena, his former housekeeper.
"He's terrific and he totally understands the situation. So, it all has worked out," Arnold told Howard Stern of Joseph in 2015. "It's a very tough situation for him. It's a very tough situation for my kids. Very tough situation for my family. It was tough for everybody. But it has happened and now we have to figure it out, right?"