Unbreakable Marriage Contract? Hah

And what, I can write up contracts that can strip the magic of any of my descendants that are inescapable? So how about one that says 'Don't be a bad person? or even 'Don't marry muggles? I can't see certain families passing that one up. And what is a marriage, anyway. If it is so arbitrary, you expect me to believe 'magic itself' or something cares about human marriage?...