"Missing the OG today. First Bday without him," Robin wrote on Instagram
Credit: Charley Gallay/WireImage

Robin Thicke marked his 40th birthday by remembering his late father Alan Thicke.

The singer took to Instagram on Friday to share two throwback photos of the Growing Pains star. “Missing the OG today. First Bday without him. Love you Pops,” Robin captioned a selfie of his father and sleeping son Julian.

And in his second post, the birthday boy appears to be sleeping in his father’s arms. “Thats me! Haha,” Robin wrote.

On Dec. 13, Alan complained of chest pains while playing hockey with Carter at Pickwick Gardens skating rink in Burbank, California. Shortly after being taken to the hospital, the actor died. He was 69.

According to his official death certificate, the Canadian native died of a “ruptured aorta” and a “standard type A aortic dissection.”

Over a week ago, Alan’s loved ones paid tribute to him on what would have been his 70th birthday on March 1. Thicke’s widow Tanya and 19-year-old son Carter wrote heartfelt messages on social media.