As a part of the Claus tradition each time a Santa retired they would choose a family that would marry their daughter to the next Santa.

The conditions of the family had to be considered wisely, because not only they had to keep that big secret and give a male heir to the next Santa, they had to be able to sustent the Claus family financialy with all of the upgrades in tools and team. The family chosen would have to be friends with the Claus family and give a certain amount of money each week until the current Santa retires and the process begins all over again.

For Arthur this was... Not somehing he likes, he would like to marry someone out of love. But Steve, he was all in if it meant being the next Santa, he was a man of profit, he would act if he sees that somehing can benefit him in some way and being the next Santa was EVERYTHING for him.

When his father told both of the boys that they had already chosen the family he was so exited the elves complained about his hiperactivity for days, he wanted everything to be perfect for when they had to meet the girl,you, so he was giving orders in all directions to leave everything spotless. But he wasnt exited about marrying you, he was exited because he was one step closer to being the next Santa, and he will not let anything mess this up.

So, the day when he would be meeting the lucky girl,you, he dressed up nice with his normal Xmas theemed military-looking uniform, he made sure his hair looked good and everyhing was alright around the base. His brother refused to get married to someone he didnt love so he had a free way to conquer your heart and finally get to be the next Santa.