Dax Shepard shares moving story of his dying father bonding with Kristen Bell's belly

By Kat Giantis

They made you laugh with their sloth-based antics. Now, Dax Shepard and Kristen Bell will make you cry. In a poignant and candid post on his Tumblr, the funnyman shares the final days of his cancer-stricken father, Dave. Among the touching moments: An unexpected hospital visit from Dax's pregnant longtime love, Kristen Bell.

"At one point, and unbeknownst to both of us, my wife walked into the room," writes Shepard (it remains unclear whether the engaged pair has actually tied the knot). "She had flown in from L.A. [to Detroit] without any warning. It was a surprise. It was an amazing, incredible, perfectly timed surprise. She lifted her shirt up and he put his hand on her swollen stomach. He left it there for the better part of an hour."

According to Dax, "He was smiling from ear to ear, sitting contently, unable to put together a sentence, but still capable of connecting to the new family member we were creating. He wasn't going to make it to the birth, but that didn't get in the way of him meeting the new baby. It was an emotional and triumphant moment. One I will never forget. If I live to be a thousand, I will still be in debt to my wife for giving him that one last thrill."

Go read the entire essay (titled "My Father's Horniness") about Shepard's sometimes-fraught relationship with his dad, who passed away late last year, not long after his belly encounter with Kristen. He was 62.

"One of the hidden benefits of cancer is that it can erode grudges the way WD-40 dissolves rust," Dax writes. "It just finds its way into all the nooks and crannies and starts loosening."

The response to his essay has warmed the heart of the "Parenthood" star. "Reading all of these beautiful responses has been overwhelming in the most glorious way," he tweeted on Thursday. "Thank you to everyone who read and shared back."

Click on for more photos of Kristen and Dax being adorable ..