Randy, that's what I mean

Under certain circumstances you could get some of the benefits for your mom (like the tax breaks) but it isn't necessarily easy. My wife and I can own property in common (which means its hers if I die, without a lot of headache) based on a ceremony in a KH thirty + years ago. If I want to do that outside a marital relationship you're talking hours and $$$ with lawyers at minimum. And that still doesn't settle issues like spousal consent for medical care.

And yes the sexual component in marriage is significant. Even most (if not all states) will annual a marriage that has not been consumated. (Don't get me started on dry spells - my marriage is still recovering from my trip to rehab and concurrent legal troubles).