Vixen and Donner's marriage ended after vixen realized she was, in fact, a lesbian, and her and donner parted ways amicably. the divorce selfie, however, was a little too far in donner's eyes.
santa claus manages the north pole, which means he also can handle any legal affairs the people of christmastown need taken care of. there ARE legal representatives in the reindeer and elf population of the north pole, but santa offered to help out his sleigh team's eldest members personally.
in all seriousness, they had a laugh about this one later.