Russia is aware that he has rather bad reputation when it comes to respecting other people's personal boundaries and borders. He falls in love and begins to woo the nation, very slowly. And very chastely. Showing a great deal of self control.

And the nation he is in relationship with is completely baffled. Doesn't Russia want them? Is Russia just not interested in sex? Is his boss being an ass and interfering? Because they never thought in the first place they might have a reason to be afraid.

Bonus: They finally get to sex and Russia is very unthreatening and, as a result, passive. The other nation demand to know if Russia even wants this because they don't have to if he doesn't, seriously. And this is the first time anyone has ever said that to Russia.