both of you really dislike each other since childhood even if your parents are close

Suddenly both of your parents promise to marry you both, she greatly wanted to annulled this engagement but her parents won't let it, so she tried to do everything for it to occur including making it seems like she can't bear children. On the first night, she would make sure to take contraceptive pill without your knowledge as she despise the idea if bearing your child and having her tied to you