VIDEO: Ashton Kutcher & Demi Moore -- 'The Secret To Our Marriage'

In their first-ever prime-time appearance together, Ashton Kutcher and Demi Moore chatted with Piers Morgan Thursday about the secrets to keeping their A-list marriage alive and kicking.

Morgan put the sexy couple of eight years on the spot, asking them, "What is the secret to a happy show business marriage?  How do you make it work?

Moore responded, "Well, one, I think you have to make your relationship a priority -- and that's a difficult balance when you have work and, you know, the combination of a career and family.

“I think part of it is, I think we spend very little time apart -- that's one of the key things.”

Kutcher said another key is "working on the relationship when the relationship is good.

"You know, as marriage goes, I think most people sort of set being -- you know getting married as the goal as opposed to being married," The Butterfly Effect star said, noting he and his wife "are both very alpha individuals."

Watch the video on RadarOnline.com

Moore also said she's got a special way of communicating sweet nothings to her hubby: Post-It notes, as she has 'em "placed in various locations all with messages of encouragement or love or just thought -- some have been there seven years."

"Post-It notes are much cheaper than diamond rings!" Ashton said.

Piers Morgan Tonight airs weeknights on CNN at 9 pm ET/6 pm PT.