Its because the last king was bi or pan and then was just a straight up pedo who specifically targeted young boys and on top of that he was also a tyrant that people were scared of which made them sceptical of same sex couples from the nobility cause they saw it as an abuse of power so shin thought it was best that they hold off on getting married until they make wolfgang look like a more than worthy king so that the ppl wont question their same-sex marriage
If you commented this on previous season, i'd agree with you. But since this season started i don't think that's still the problem. As you can see, the princess is already a teenager which mean Wolfgang has reigned as the King for more than 10 years. There are also many scenes that shows how the folks love seeing Wolfgang and Shin together and even supported them, literally the whole kingdom ships them. People will not question their marriage anymore
I'm so confused why Wolfgang and Shin are still not married? Even the princess has already that grown and the whole kingdom already knows they are dating, what are they waiting for????（/TДT)/