OMG i just realized that after reading your comment ... FUCK!
They are not at married couple yet, also I thought so too. Because in chapter 65 near the end she says: „Make me the most beautiful bride in the kingdom.“ Seems she is his fiance in the moment.
In chapter 66 they call her the duchess and say she is his wife..? Either you're wrong or I can't understand English
Hmmm... I looked at the meaning in the internet and it says you are only called a bride till one day after the marriage. But maybe there are more hmmm... stages of beeing a bride where the manga (webtoon? Manwha?) comes from? It‘s really irritating.
WAIT WHAT HOW COULD THEY DO THIS TO US?! THEY DIDNT SHOW US THE WEDDING LIKE WTF HOW IS THAT EVEN POSSIBLE