According to Star magazine, Ashton Kutcher and Demi Moore’s alleged open relationship may have doomed their marriage.

When Ashton and Demi first met 8 years ago, the fires of passion (fueled by Dopamine) burned inside them. Often when two people are sexually attracted to each other, they confuse that sexual attraction with love. For most people, the reality usually sets in between 6 months to 2 years when the Dopamine stops leaking.

According to Star magazine’s sources, Ashton and Demi agreed to an open relationship in hopes of keeping the fires burning. There are also reports that Demi was bisexual.

“Everyone in Hollywood knows about their arrangement, but they’ve managed to keep it a secret from the general public,” a source told the magazine. “Demi is attracted to women just as much as men … She was cool with Ashton having flirtatious relationships too. Somehow they made it work all these years. Both of them were respectful of each other. It was a lot of fun for them.”

The writing was on the wall when two women came forward with stories of passionate sex and wild nights spent with Ashton. At first, Demi and Ashton denied the rumors on their Twitter pages.

But yesterday Moore announced that her marriage to Ashton was finally over.

“It is with great sadness and a heavy heart that I have decided to end my six-year marriage to Ashton,” she said in a statement. “As a woman, a mother and a wife, there are certain values and vows that I hold sacred, and it is in this spirit that I have chosen to move forward with my life.”

Ashton followed up with a comment on Twitter. He said, “I will forever cherish the time I spent with Demi. Marriage is one of the most difficult things in the world and unfortunately sometimes they fail.”