If she is fluent in German (or even better, if she isn’t) how about “Gute Freunde” (Hey we can remain good friends) by WIZO?
I bet there is no better song in any language in case someone really dissed you… like the OP describes. Lyrics translate to something like this:
Basically, everything was as always
When I came to her the other night
We went to her room, as always
When she suddenly took me in her arms
She looked at me from her big eyes
And then suddenly turned quite serious
And then came the thing why I hate her now
I hate her yet I still like her
With a few lousy phrases she pricked holes in my brain
I could not believe it, because I didn’t want to lose her
b
“Hey we can remain good friends”, she said to me
After that I longed to put a bullet through her head
“Hey we can remain good friends”, she offered
And I still ask myself today: Why didn’t I beat her to death?[/b]
…