I feel that this song is not necessarily about cheating. I agree with the long-distance idea. That is the feeling I got from it. I think maybe he had this girl, and then he moved, and they ended it because the distance was too hard. But then, for some reason, the idea of them getting back together comes into play ("Running with scissors wasn't smart / I tripped and cut open your heart / I didn't mean to, but I seem to / Have pushed us back to the start") and now they are back to the hurting of the long-distance thing again.
I feel that this song is not necessarily about cheating. I agree with the long-distance idea. That is the feeling I got from it. I think maybe he had this girl, and then he moved, and they ended it because the distance was too hard. But then, for some reason, the idea of them getting back together comes into play ("Running with scissors wasn't smart / I tripped and cut open your heart / I didn't mean to, but I seem to / Have pushed us back to the start") and now they are back to the hurting of the long-distance thing again.
And I love Hot Hot Heat.