It's not that they physically have sex differently, but that the barrier to entry is less emotional. I dated a Belgian girl for about a year and a German for around 4 months. With each of them sex was much less something with a lot of strings attached in terms of relationship status and commitment, and instead just something fun to do with your body with someone you trusted.
Another thing I was told (and I'm no expert on Belgian culture) by her was that having sex was considered less intimate than giving a blowjob. So oddly enough, we just skipped 3rd base and rounded home. She didn't give me head for months after that when we had fallen in love. So while she had been with a half dozen other men by that point, she had never given a blowjob because I was the first serious relationship that she had been in. Comparing that to American culture where a blowjob is a way for a girl to give a man sex without giving him her body, and you see a pretty stark difference, and an example of what I'm talking about.