Flight or Fight....and she chose FLIGHT 🤣
Serenia and the Duke's situation is kinda confusing and added misunderstandings. Plus his maids treatment to the MC.
Additionally, he only chose a "quiet, well-behaved and docile" fiancee when another woman is living under his care. I doubt that their relationship is simply Serenia teaching the Duke on sword techniques. Plus, it is questionable how Serenia gained royal support.