I am even more adamantly opposed to going after swingers or polyamorous couples. If two adults consent to living that arrangement, as many do, that is even less the business of the military. If they are flaunting it at work, that should be dealt with. The same can be said for the single E-4 or E-5 who makes others uncomfortable talking about a different bar skank every weekend. Have a talk with them about keeping their personal activities a little more quiet, and carry on.
It is far from hubris for someone to want to be a swinger. It is a religious interpretation of relationships that attempts to force people into monogamy, and punishes those who practice otherwise. If you want to be monogamous, great, go for it. If you are in a swinging, or poly, couple, and all parties consent, who cares? If you commit adultery, it's between you and your spouse. If someone who works for you has a problem with it, then they can be adults and move past it. I disagree with things my leadership believes or does, and it doesn't affect my ability to do my job. Because it doesn't matter. If the subordinate is so distraught over adultery that they cannot manage to function at work, then that's their own problem. People make mistakes. On the list of things that would make me want to work for a different officer, adultery doesn't make the cut.