I broke a girls heart
How did you break it?
I had a quarrel with her father over a landline a few years ago.
It's awful to do that to someone. Apologize for hurting her.
It wouldn't matter even if I apologized. I'm feeling awesome after hurting her
If things won't work out you should break up but you don't have to be vicious about it. Sometimes you just can't tell how someone might react.