Jake Reiner, son of the late Rob and Michele Singer Reiner, is speaking out on his parents' deaths in an emotional new essay.

"Nothing can prepare you for what it feels like to lose both parents instantly at the same time. It’s too devastating to comprehend," Jake Reiner wrote in a Substack essay titled "Mom and Dad," published Friday, April 24. "I still wake up every morning having to convince myself that, no, it’s not a dream. This truly is my living nightmare."

Jake Reiner said he "was robbed of so many things that day," he wrote. "My parents won't be at my wedding, they won't get to hold their future grandchild, and they won't get to see me have the successful career I'm still seeking. It simultaneously breaks my heart and enrages me."

The acclaimed "Princess Bride" director and his producer wife were found dead in their Southern California home on Dec. 14. Days later, prosecutors filed criminal charges against their son, Nick Reiner, who is accused of "fatally stabbing" his parents.

Jake Reiner also revealed the moment he learned about the deaths of his parents.