And thinking jealousy might help. Whereupon I remembered I was setting this in a world where lots and lots and lots of fairy tales come true. All I needed was some.
Contrary to pop culture, not all fairy tales end with a wedding. They don't even always have one at all, whether at the end, or in the middle, or the rare at the beginning. But there's a lot of them that do. Some even have variants where it's a nobleman, not a prince or king, that marries.
The fun part is picking ones where the hero of another story can watch it unfold before him and get jealous. Not all stories make good spectator sports. Like, oh, The Master Maid, where the hero finds the title woman when he's working for a troll, and then after their escape, he's magically induced to forget her.
But some work. Even skipping Cinderella because it's in the pop culture Top Twenty, there's Cap O'Rushes or Catskin, to have three balls. Or have the nobleman bring his bride from the forest a la Brother and Sister. Which even gives the prince a role to play, since the stepmother and stepsister end up executed at the end.