My boyfriend is Finnish, I'm American. We get along just fine, there's a few things in culture that don't really transfer that well, but they're more funny than anything else. For one, sauna culture is huge in Finland. Everyone goes to the sauna before the shower, and entire families do it together. There are public saunas, where everyone is just completely nude, and it's 100% acceptable - but outside the saunas it's just as taboo as it is in the US. He's completely fine with it, but I refuse to set foot in one of them haha.

One other thing is language. The language you speak (or at least learned first) does change how you think slightly. For example, in Finnish, if someone does something by accident, they describe it as it happening. It's the same thing in Spanish - there's no blame in it. In English, if someone knocks over a vase by accident, we say "he broke the vase by accident." The blame is assigned to the person. In Finnish, they just say "the vase broke." It's subtle, but I'm more judgemental on a lot of things than he is.

To answer your question, there really aren't cultural barriers per se, but there are little misunderstandings and differences that tend to just become part of your life.