Just what is Danke Shoen about, anyway?

I’ve read the lyrics while the song is playing.

Did they break up? Was she cheating on him? Why’s he thanking her if she dumped him?

And is the part about her tearing her dress supposed to be suggestive or was it just a convenient rhyme?

I think the two people were lovers at one time, but just parted ways and are reminiscing.