Katherine Schwarzenegger has a heartwarming birthday wish for dad Arnold

Katherine Schwarzenegger’s latest birthday post for her dad Arnold

is too cute to handle.

In an Instagram post on Saturday, the mom of two, 32, celebrated The Terminator star's big day with a series of loved-up photos.

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.

In the last picture in the gallery, a more recent one, Arnold is shown carrying Katherine and husband Chris Pratt's one-year-old daughter Lyla Maria.

"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.

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."