The former lovers sat down for a candid chat about their 2007 romance on the latest episode of Dax's Armchair Expert podcast.
The two stars hooked up as Kate's marriage to rocker Chris Robinson fell apart and before she found love with Muse frontman Matthew Bellamy, and Dax confessed he felt a little lacking as his girlfriend's career was really taking off after the movie hits "Almost Famous" and "How to Lose a Guy in 10 Days".
"I felt very less than around you quite often," Shepard told his ex. "I felt very much like, 'F**k, I don't know what I'm doing. I'm following this person around as they do things I wish I were doing'. I felt all kinds of inadequacy in that position."
The couple split as friends and remain close, with Hudson admitting she had a great laugh with Dax: "We laughed our a**es off," she recalled."
Shepard went on to reveal they met at a party at Tobey Maguire's home and hit it off, but the actors were both in other relationships at the time. They eventually met up two years later when they were single and tried to plan an intimate dinner at Malibu, California restaurant Nobu.
"There was a bunch of paparazzi outside," Shepard said. "And while we were there, we said, 'Wouldn't it be funny if we came out holding hands? And I was your new boyfriend'. We were just pals."
"And then we added, 'Wouldn't it be great if her new boyfriend didn't wear a shirt at Nobu?'"
"I almost peed in my pants, it was so funny...," Hudson added. "Then I wanted to have sex with him. It was, like, the perfect move."
The pair dated for three months and Dax credited Hudson for teaching him how to communicate better and be vulnerable.
After they split, Shepard met his now-wife, Kristen Bell.