...but apparently you can be extra-married. Will Baude thinks covenant marriage is legally OK but that there's something icky about it, and, while I have no legal expertise, I'd have to say I agree with him. But what I don't totally understand (from a social, not legal, perspective) is how covenant marriage can exist without making regular marriage start to seem flaky, to say nothing of civil unions, which, under the new framework, start to look a bit like agreements to be dates to a junior high school dance. Ideally, if marriage has to be written into law at all, there'd be just one thing, called marriage, and couples could define it as they see fit, and take it as seriously as they'd like within the bounds of the contract. If covenant marriage takes off, heterosexual couples who choose marriage over covenant marriage will start to seem unsure about the commitment they're making. Also, if one partner wants a marriage and the other would prefer a covenant, that could potentially be a large but otherwise avoidable source of conflict.