so, I’ve gotten this question and similar ones before, and I want to use it to go into what marriage actually is.
so, in law, there are a couple of legal assumptions made when someone is a close family member, like a parent. the assumptions are that this person knows you well enough to make decisions on your behalf in an emergency, supports or is supported by you financially, and, most importantly, that they are emotionally significant to you in a way that makes them different from a total stranger or a good friend. immigration law, for example, prioritizes families over people immigrating for jobs alone, because not getting a job doesn’t have the same emotional weight as never seeing your mom again.
the difference is that you don’t get to choose your family (outside of adoption and, uh, legally that’s not a bilateral decision). you do get to choose your spouse. the fact that you chose them is why they get priority for things like inheritance and immigration, even over your parents or your siblings or your grandma.
how does the government know that this particular person is someone you want to have as part of your family? you fill out a form and you tell them.
what happens if you don’t want them in your family anymore, and don’t want those assumptions made about them? you fill out a different form and you tell the government that.
the thing I think that’s hard for people to wrap their heads around – whether you’re a starry-eyed romantic or a pragmatic bitch like me – is that marriage isn’t an announcement of how much you love someone. that’s what a facebook status update is for. you do not need to be in love, or sexually/romantically monogamous, or be religious, or any of the other things people associate with marriage, in order to be married.
it’s a legal decision. it is choosing to get certain benefits (like taxes, because it’s assumed you’re financially supporting each other) in exchange for certain responsibilities (because it’s assumed you’re supporting each other, it stops mattering exactly who bought what after you got married, so divorce splits the whole pool of stuff even if one person bought like 75% of it).
you don’t get the one without the other, and you don’t get either if you don’t affirmatively say that’s what you want to have happen. it doesn’t happen automatically, or in every romantic relationship no matter how serious, because the choice is the point.
and, to be clear: if you do not want, or do not care about, the legal rights and responsibilities of being married, you should not get married. it’s a fucking legal contract that has serious legal implications! it’s not something you should be doing for funsies!
tl;dr: if you want all the shit that comes with a marriage, good and bad, you need to tell the government that’s what you want. if you don’t want it, then you don’t need to do it, but you need to also be aware of what you’re potentially losing (in exchange for what you’re keeping). that should be an informed decision, not one you make for emotional reasons like “I just want everyone to know I’m only having sex with this person forever” or “our love is so pure it transcends legal boundaries.”