A stereotypical antipattern:
1. A Swedish girl and a British guy meet and start living together in Sweden. (Yes, somehow, it tends to be that gender config.)
2. Since "everyone in Sweden" speak at least a little English, the guy doesn't bother learning Swedish.
3. The British guy can't get a job since he doesn't speak Swedish.
4. The British guy gets bitter and starts posting in the forums at thelocal.se, (run by bitter UK socialists who went through the same thing and are now super angry at Sweden).
5. The couple breaks up, hopefully before having kids together.
6. ...
Culture clash is real.