Wilfried, Wolfgang was quite correct - 'Dat du min Leevsten buest' is THE Low German night visiting song. Whenever I hear one of the innumerable maudlin renditions preferred by our radio stations (and some bands) I ask myself, Don't they realise this song is about SEX?
Slight correction to Wolfgang's last post as well (sorry!): The language of 'Trina' isn't Frisian but Low German, from the west coast of Schleswig-Holstein where I was born. I would have a lot more trouble understanding it if it was Frisian, but I was brought up speaking Low German, and the lyrics are quite familiar.