Katherine Schwarzenegger is celebrating her father Arnold’s 75th birthday!
In the first, the duo is riding horses as Arnold jokes around with a peace sign behind her head. This is followed by pics of a young Katherine climbing her dad’s arms in the pool and one of Katherine and sister Christina being all smiles as their dad holds them in the air.
“Happy birthday daddy!! We love you so much!” Katherine wrote in the post caption. “You’re the best and most fun opa and dad and we are all so lucky to have you in our lives! Happy happy!!”
While appearing on Jimmy Kimmel Live! in February, The 6th Day actor gushed about his growing family.
“It’s the easiest thing to be a grandfather,” said Schwarzenegger. “They come over to the house, you play with Lyla for around an hour or two, put her on the horse, put her with the dog. And after two hours, they leave,” he joked, clapping his hands in front of host Jimmy Kimmel.
“It’s fantastic! I have a great time when they come over to the house.”
Speaking about his son-in-law, the former governor of California called Pratt, 42, a “fantastic guy” and “a great son-in-law.” Sharing similar praise for his author daughter he continued, “I love my daughter. Katherine is so wonderful and I’m so proud of her.”
“When they come over the whole house lights up,” he added.
Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
Last month, it was Pratt’s turn for celebrations as he turned 43 and received an Instagram birthday tribute of his own.
“Birthday Boy!” Katherine wrote in her caption. “Happy birthday to you! We love you so much! I feel like the luckiest in the world to live life with you.”
Katherine went on to sing Pratt’s praises. “You’re the most loving father, the most supportive partner and you have the biggest heart and we are so blessed to feel and witness your love,” she added. “Happy happy handsome.”
Alongside her words, Katherine also shared a gallery of intimate photos of Pratt throughout the year, including pics of the two posing together and one of Pratt holding his wife in his arms for a kiss.
Pratt and Katherine have been married since 2019, they welcomed their second daughter Eloise Christina in May.