On a grand scale: That’s what states are for. On a personal scale: If states let people go hungry, don’t make their life harder than it already is, don’t be an asshole.

That’s Captain Raynolds Galactica!

You’re missing an important part in what marriage does: Formal representation for each other, may it be law or health. That means you have someone can make decisions for you if you’re not able to (or get information about your where abouts). If both expect to stay together some time it simplifies a lot of things.

And if it turns out you don’t like each other anymore, there is always the option to get divorced.