It seems to me the only ethical solution is to have a strong sense of community, culture, and ethics. It helps me realize the validity of religious association and marriage, because, otherwise.. well, you have these problems.

It is incredibly hard to legally establish consent after the fact, especially for such an intimate connection as sex, yet somehow I feel like making it a state function is a perversion of the original intent of the spiritual matrimony.

Divorce is a terrible thing, and is a signal of a failure of an entire community, and it is wrong to hold just one party accountable, or either party, when it is a communal process. Child support shouldn't even be a thing, honestly, but the modern state of affairs with easy travel, people moving around to every new community and being constant strangers definitely makes it harder for a community to justly enforce any kind of communal support for these widows, divorcees, and the bastard children.

To be fair, there has been a lot of racial tensions and hatred leading to nonviolent warfare that has really fouled things up. Maybe these problems wouldn't even be an issue if these people weren't all a bunch of jackasses.