[John O]

To say that one is merely using the other if a couple lives together before marriage is overly simplistic

Note that I never said in all (at least I don't I ever said in all). I said in most cohabitational situations the guy is using the woman. I stand by that.

[null and void]

I said in most cohabitational situations the guy is using the woman. I stand by that.

You say that like it's a bad thing...

A bit more realistically, it must be serving some need of both parties, or one would leave.