Help deciphering lyric?

In the following song, the lyrics start off with:

*I'm much older in my body than my heart. I'm more wicked in my mind than in my <blank>*

For whatever reason, I can’t parse that last word. I’m not sure if I’m hearing it correctly, and it just doesn’t make sense, or if I’m hearing the wrong word. Anyone have an opinion as to what it is?

I’m hearing either “pen” or “pan”. Of the two, I’d vote for “pen”, but I’m not seeing how that flows from a wicked mind.

My theory:[spoiler]I hear “pen” as well. It means he bites his tongue when he’s writing things down, so his mind is much more evil than his pen.

This flows from the previous line, which indicates immaturity: He’s much older in his body than his heart because he hasn’t fully grown up, so he still thinks a lot of mean, childish things that he’d never write down.[/spoiler]