Ashton Kutcher and Demi Moore have learned how to keep their eight year relationship going strong ... and "magical" Post-It notes may have been the key!

While appearing on Piers Morgan Tonight, the twosome opened up about their personal life. When asked if Ashton is a romantic guys, Demi tells Piers:

    "I would say so. The type of romantic is, you go to our house, I have Post-It notes placed in various locations, all with messages of encouragement or love or just thought. Some have been there, I don't know, seven years."

As for how they've remained such a tight couple, Ashton adds:

    "It's working on the relationship when the relationship is good. As marriage goes, I think people set 'getting married' as the goal as opposed to being married. Working on it when it's really good, not letting it go flat and finding things to work on together..."

Find out more about their project Real Men Don't Buy Girls ... after the jump.