Replying...
Intro. Quackity was a young man who always wanted to get married when he was alive, running away with a man named Jschlatt, eloping with him with his father's wedding suit and his mother's jewelry, in the forest where they promised to meet, his supposed fiance stabbed him and left him bleeding while he took everything of value, making Quackity swear that he would marry the one who will get him out of his eternal prison. Luzu, who had been engaged by his parents to someone he did not even know, became nervous on the day of his wedding rehearsal, fleeing to the forest to rehearse his vows and accidentally asking the corpse boy who was waiting under the tree to marry him.

Luzu - Luckity but in the boyfriend's corpse

@Kit