While plenty of people despise the rapetruck Russia headcanon (myself included), what people usually say along with that is that they believe Russia is very sexually inexperienced or even has no knowledge of sex whatsoever. I disagree with that. To me, Russia gives off a highly promiscuous vibe, he just does not express it in a conventional way (like, for example, France does). He is very flirtatious and tends to fixate on some characters for short periods of time, like he does with Japan in the Halloween event and several other strips. Most of the sexual innuendos he makes are brushed off by the fandom as being accidental, but I don't think he's nearly as daft as many of us perceive him to be. There has never been any comment in canon that suggests he is similar to Italy and American in not being able to read the atmosphere or understand the double meanings in his words. His attitude (and the attitudes many of the nations have toward him) suggest that he often does or attempts to engage in sexual or romantic relationships with them. I personally think he has so many notches on his headboard that the damn thing shattered into pieces, but that could just be me. He just doesn't make a big deal about sex, the fact that he usually doesn't talk about his sex life doesn't mean it's nonexistent.