What’s the difference if men and women live by themselves and have people come over, engage in dating, and having sex? The root cause of the effects of cohabitation is economics, not morals.
The preferable arrangement is to go over there.
You mean like being a collecting "single mom" who actually has a live-in boyfriend who works under the table? Yes, that's certainly one cause of cohabitation. But among the middle class, cohabitation is very often seen as a "trial marriage." I've seen that among my peers.