After a few drinks, England takes another nation home for a bit of how's-your-father. In the morning his lover is not in bed when he wakes up and England assumes s/he left. He goes downstairs to find his lover in the kitchen having breakfast with Scotland and Wales. Scotland and Wales proceed to embarrass the shit out of him by doing things like expressing surprise that he bagged such a hottie, asking his lover if England still farts in bed, scolding England for not getting up early and making his lover breakfast etc.

Bonus: England and the other nation have been together for a while, but he never brought him/her home because he knew this would happen.

Bonus 2: The other nation regrets the one night stand and was actually trying to sneak out when Scotland and Wales spotted him/her.