Well, at least they tried.
Before announcing their separation, the couple had already been living apart and dating other people and were clearly living separate lives, but friends say they did try to make it work one more time.
A source says:
"They've never had what most people would consider a normal relationship. It started out good, but it didn't end that way. They tried to find common ground, what held them together all these years, their love for their daughter Coco.
She's tough but feels a tremendous sense of loss. It's hard to walk away from a marriage, even though she hasn't been happy in a long time.
Courteney and David will be tied together for life by their daughter. Plus they both went through her infertility issues, miscarriages and all the heartbreak that went along with that. But it just ended in fighting and anger.
Things changed dramatically though. David slept with another person. Courteney has feelings for her costar and a complicated marriage became even more complex.
They got together secretly and tried to talk through their issues. They cried. They remembered some of the great times they had but then they started to fight."
That's when the couple knew it was time to end things and announce the end of their marriage.
[Image via WENN.]