Honestly I'm a huge hater of this kind of blackmail plot UNLESS MC gets back at her eventually. I'm gonna stick around and keep reading to see if that eventually happens; usually it doesn't in this kind of manga but the doormat MC at least tried to decline at first so it wouldn't be completely...
The wedding / romance in this manga feels so forced. Like there hasn't been any real time for the MC and Brauer to bond yet they keep being pushed into the whole wedding thing...