Dirty Little Secret

I like the song "Dirty Little Secret" by the All American Rejects. I always thought the lyrics describe a private, passionate relationship—one that could be hurtful to those who discovered the sinful secret . However, I recently watched the video and now I'm not so sure.

I instantly enjoyed the video. Instead of a secret relationship, the faceless people in the video seem to expose the one secret they are most afraid other people will discover. I'm not sure why he says "I'll keep you my dirty little secret," since it seems like he is giving his secret a formal identity. That's why I wonder what the song is really about. Anyway, the video is cool so check it out. You can also find it on myspace.

The song triggers one of my pet peeves. Instead of ranting about the blatant disregard for grammar in pop music, I'll just point out that he should be singing "You are the only one who needs to know!"
What (who) is your dirty little secret?