Usually, the season's fun would start with the decoration. Hanging all those trinkets at the tree… and at the Asian's back when he wasn't looking. Of course, US would end with a bunch of said decorations on himself, the other year Korea even managed to hung a Santa mini-doll on his glasses.

The artificial snow spray always had messy outcomes that would make them laugh at each other for earning Santa style beards and hair or looking like snowmen.

When decorating the ceilings, he would hold the ladder, occasionally shaking it to freak his partner out. After the first times, Korea got used and would just show his tongue or finger and, after finishing, jump from the top of the ladder just for the hero to save him.

Then, US warned the Asian to 'Keep away from the dreadful mistletoe, it's there for very French purposes.'

The brunet would giggle and suggest to 'Keep said purposes a secret, or Russia would hang one on his own hair and try to make the world become one with him da ze!'

They would go together to the mass. From time to time, he would be poked and hear a whisper asking about something the father said. The typically bubbly Korean would be serious and thoughtful.

Later the American would wonder that a fun lover joker like his friend had a religious internal struggle with Christ Vs. Confucius…and tease about how cute that was, while the brunet pout declaring Christ and Confucius working great together did originate in Korea.

Because they both obviously originated in Korea.

On the way back, they would sing carols… that would end up with crap lyric versions most of the time, making them laugh.

If not, they probably would be snowball fighting out of the blue and just stop when one of them gave up… and that always took time, since the Korean was stubborn and no way the hero would accept defeat!

At dinner, Korea would joke about Turkey always having the spotlights at the table.

Everybody (or almost) would drop by, even if just to greet. He house would be a merry mess of nations coming, singing, chatting, eating, drinking and going – not necessarily on that sequence.

And when the guests leave they would watch movies about the season until one of them end up sleeping on the other's shoulder.

Notes:

Even if there is still a huge Confucianism influence on South Korea, there are many Christians as well. At least in Brazil, there are many Korean Christian churches. Not sure, but I believe their religion is a mix of the two of them.

Christmas is an official holiday in South Korea.