If you're talking about Anastasia the princess, you don't have to marry her to get her. It is possible to talk her into becoming your slave willingly. Or you can just shove a mindbreaker potion in her mouth and turn her into an empty husk, but I don't know if you're willing to count that.
She also does not die, but she does become unobtainable, which may be another distinction without difference.
My bigger concern with the mastery points is that some of them seem way better than others. "You can start with the ability to put everyone to work without having to spend points on unlocking the ability to make them work or fight" seems way better than "you can get anybody pregnant," especially since the ability to ignore that can be unlocked via Loyalty, and is only really relevant if you're playing as something exotic and want to make a lot of kids.