After 55 years of marriage, a family therapist shares his advice on what it takes to make a relationship last.

For decades, researchers have tried to decode the secret of how to make a marriage work long-term. We still don't quite seem to understand why some marriages flourish and other marriages fizzle.

Add Yahoo as a preferred source to see more of our stories on Google. Marriage can sometimes feel like you're trying to solve a puzzle with pieces that keep changing shapes. But then you see those ...