When your boss is sleeping with one of your co-workers, how do you know that they are not in a quid-pro-quo relationship?
This isn't an American thing - this is a workplace thing.
If you're a manager, there's seven billion other people in the world, who don't report to you. You'll probably find your soulmate, or whatever the hell you're looking for - outside of your reporting chain.
And as I've said in just about every post I've made, he should've been fired for sleeping with a subordinate. There are countless reasons that's not OK. I was responding to and quite obviously referring to the guy making a big deal about him telling someone he "owns them" - or whatever terminology he used. Do I think that's disgusting? Sure. But that's between him and whomever he has that relationship with. If she's consenting and willing, so be it, not my place to judge.
I don't understand why Americans are so concerned with what happens in somebody else's bedroom. I don't give a single flying f about what two consenting adults decide to do in a bedroom. There are all sorts of sexual kinks that I find disgusting and sometimes disturbing - but it turns out it's not really any of my business. The second you introduce a non-consenting adult, or someone not old enough to consent, then we've got a problem.
Otherwise - why do you care? It's none of your business.