What is this? A third party is trying to get them divorced? Yet the two people who are married don't want a divorce. Him saying he doesn't love her doesn't count enough as evidence? He could kiss that bi*** a hundred times doesn't mean he loves her, plus they cut off the duke's statement. He is a duke. Plus they are nobles love and marriage don't necessarily correlate since arranged marriages are so common.
Now if the crown prince ordered a divorce that may be possible, but that doesn't seem to be the case at all.
This is just so dumb, and I liked this story too, but whew even my this is a different world with different rules argument can't make my brain accept this nonsense.
Read Cursed Princess Club, it's finished and fantastic.