Josey Dorsey is going back to school.
"Dear Summer, What happened? How'd you go so fast?," he wrote on Instagram on Aug. 23. "Kindergarten just ended, Now we're in 1st grade class!?"
The Big Sky actor applauded his "big boy" and wrote, "I Love you so much."
Two months earlier, Ryan, 39, celebrated with Josey at his kingergarden graduation and marveled at just how fast their son is growing up.
"Can't believe it but it's officially [peace sign emoji] out Kindergarten !!!" he wrote in a June Instagram post, along with photos from the big day. "My baby boy is really a big boy now on his way to 1st grade?!"
Ryan and Naya were married from 2014 to 2018. Two years after their split, the actress, then 33, drowned in California's Lake Piru while boating and swimming with Josey.
According to the investigative and autopsy report, obtained by E! News, Josey told investigators that he and Naya jumped in the water after counting to three. The report states, "shortly after they jumped in the water, the decedent told Josey to get back on the boat. She helped him onto the boat and he then heard the decedent yell 'help' and she put her arm in the air. She then disappeared into the water."
Ryan previously praised their son for his strength and bravery following the loss of his mother.
"This little boy...man...I couldn't be any prouder of someone, " he wrote in Instagram in January 2021. "At such a young age, he's endured more than anyone should at 5 years old. Without even fully realizing it, he lives the #keeppounding mantra every day with his resilance [sic]."
He continued, "You're so strong, so brave, and so kind. I will always be proud of you."