It' s obviously manipulative and wrong. In no way would this be acceptable in real life. Regardless if the marriage was prearranged or not, "marking" the girl and entrapping her through impregnation or marriage is an abuse of power and similar to enslaving a woman. Worst of all is how it's under the guise of "true love." The idea that if you're in love with someone, it's acceptable or even encouraged to do whatever you can to "get the girl," despite her obvious protests, makes for a pretty messed up world view.
But god damn does that get me wet. Personally, as long as you aren't thrown aside like a used cumrag, there's nothing hotter than a hot guy literally marking you as his through whatever means necessary. It's a pretty hot fantasy, even if it is problematic. But as long as it doesn't induce overly aggressive behaviors, like impregnating someone against her will, it's fine to enjoy the fantasy. You don't need to read it if it doesn't fit your tastes. It is pretty niche afterall.