Many couples who try to date while married do not realize how laborious it will be. “If this is truly a situation where the couple has mutually decided to open their relationship, then it’s a boon that de Blasio has time on his hands, because these relationships tend to require a great deal of time-consuming and emotional conversation in order to work out well for both people,” says Daphne De Marneffe, a therapist from San Francisco and author of The Rough Patch.

Others advise against it for exactly that reason, especially with high-profile marriages, which are already tricky to maintain. “I caution against adopting this ideology due to the fact that it only complicates an already complex unit,” says Bridgette Reed, a marriage and family therapist from Dallas. “The more people you add to that unit, the more complicated it becomes and the more strain you put on the relationship long-term.”

[Can it ‘work’? It depends on what ‘work’ you want to accomplish. If you want to end a marriage, then yes, this is a very successful strategy to accomplish that aim. If you plan to stay married, then no, not at all. It’s not even a great strategy on the *dating* side of the equation. What kind of people will be attracted to someone who can’t commit to the marriage he’s in and won’t be open past a certain point to any serious commitment? If DeBlasio and his wife are looking for fulfillment rather than just casual sex on the side, the odds are stacked against them in all aspects. — Ed]