O'Neill's definition of open marriage was more about opening oneself up to the world and not focusing on being a couple and nothing more. Interestingly, that is still the best marriage advice around.

There are plenty of things from the 1970s that should remain in the 1970s: disco, the polyester leisure suit, and "open" marriage. Unlike disco, there are some people who think that open marriage ...

I'm in an open marriage. Well, to be simultaneously more and less specific: I'm in a nonmonogamous marriage. An "open" marriage, in the nontraditional world, means that the couple may be having ...

An open marriage is one where both spouses consent to their partner having relationships with other people. Experts weigh in on how to define an open marriage.

Find out why one woman decided to enter an open marriage with her husband and how it has improved their relationship.