I'm having such a hard time deciding who Prussia and Romano would ask. Not their brothers because Romano wouldn't want to touch Germany, and if Italy was there, Romano would worry that Prussia is going to pay more attention to him. Also not Spain because then it would be Prussia's turn to feel jealous.
Maybe someone who doesn't otherwise have much to do with either of them. Heck, maybe a woman because that would smoothen some of the flaws in Romano's personality and tone down some of Prussia's ego since I like to think he's less confident with women than men.
But at the same time, I can see even combinations like Prussia/Italy/Romano working well if the circumstances are right. Just not necessarily as a casual invitation to an already established relationship.
Re: Threesomes!
Maybe someone who doesn't otherwise have much to do with either of them. Heck, maybe a woman because that would smoothen some of the flaws in Romano's personality and tone down some of Prussia's ego since I like to think he's less confident with women than men.
But at the same time, I can see even combinations like Prussia/Italy/Romano working well if the circumstances are right. Just not necessarily as a casual invitation to an already established relationship.