Professor W. Bradford Wilcox in the Washington Post shows why "Savage Love" is stupid:

.. what is the problem with a little “nonmonogamy” in marriage, so long as everyone is open and honest about it? There are at least five problems with open marriage.

1. Even today, sex often results in pregnancy.
2. Monogamous, married sex is more likely to deliver long-lasting satisfaction than the quick thrill offered by infidelity.
3. People often do not realize what they are really consenting to when it comes to open marriage.
4. Swinging increases your risk of acquiring a sexually-transmitted disease (STD).
5. Open Marriages put children at risk.

Professor Wilcox expands on each of these points citing evidence and studies, and goes on to say:

When it comes to marriage, one of the few bright spots to emerge over the last forty years is increasing public support for sexual fidelity—in both theory and practice. Indeed, social science tells us that married couples who remain faithful to one another enjoy higher-quality marriages, lower rates of divorce, and, yes, higher levels of emotional satisfaction with their sex life. Sexual fidelity also increases the odds that children are born into and reared in a stable, two-parent home.

For all these reasons, and even though Savage is right to point out that fidelity can be a difficult virtue to live, turning the clock back to the swinging seventies is a stupid idea. Better for the sake of adults, children, and marriage as an institution to keep the book closed on open marriage