They work together, somehow. The three of them do.
France is sometimes lecherous, sometimes romantic, sometimes playful, sometimes annoying. When he is romantic, England likes to kiss him deeply; likes to wrap his arms around France's neck and tilt his head back just the smallest bit and press as close as he can. When he is playful, America likes to play and prod back, volley insults that have nothing harsh behind them and which dissipate into laughter between them until they peck each other on the lips.
When France is lecherous, America blushes terribly and laughs until he moans instead. When he is annoying, England either ignores him or does his very best to be irritating back– and he often succeeds at the latter.
Nowadays, they laugh more than they argue. They smile more than they scowl. They make love more than they fuck– which is quite strange to England and France, those savage old empires, but less so to America, who has nearly always known more gentle hands. It seems, in fact, terribly odd to the two eldest that they should look at each other and feel anything other than hatred. Neither are quite sure when the animosity faded (or simply vanished, as it were), only that it has been replaced with something that leaves a better taste in their mouths.
America has never really known hate and is thus sweet. Sweet in nature, sweet in looks, and so very sweet under their tongues when they feel like spoiling him– which is often.
When England is feeling insignificant, America is there to look him in the eyes and smile like he is the most important thing in the world. When America is bending under the weight of the world's expectations, France is there to lend his own considerable strength. When France stares out the window during a rainstorm, remembering all he has lost, England is there to squeeze his shoulder and remind him that at least one person has remained by his side.
They work together, somehow.