My love, goodbye now with lipstick on your arm when you passed out
I couldn't bring myself to call except to call it quits

Best friends, ex-friends to the end,
Better off as lovers, not the other way around
Racing through the city, window

The story:

I have been singing this song totally wrong the whole time they have had this album out; in fact, I realized I had the entire song memorized WRONG.
I didn't know how wrong I was until I was looking at someone else's misheard lyrics and I saw what the real ones were. So, being surprised, I got out the lyrics booklet and looked up the song. I had read all of the lyrics before, but this shock of mine read on my face like none other.
I have sang this song before at the top of my lungs in the car, with friends, at their birthday parties, and at a band practice of mine [I'm surprised no one corrected me, but I guess that's just how it goes when you know Fall Out Boy better than anyone in your band].