Pro-tip (for both unmarried men and women): You can sign a pre-nup even if you never have any nuptials. It turns out that people can choose to enter into a contract with each other at any time. There are plenty of reasons why people in a relationship may choose not to get legally married, but that does not mean you have to leave yourself at the mercy of the defaults in the law, which may or may not make sense for you.

This is especially important if there are children involved in your situation.