Germany and Italy are very loud during sex.... And Thor house has thin walls....

And when Italy or Germany asks why Prussia or Romano look so tried they say...

Prussia will say: "sleeping is for the week! And I am awesome!!!!"

Romano will say: "just move out of the house with your German boyfriend already! Then if you do have sex at least I won't be able to hear it!"

So they all moved out to be with their boyfriends.