I'll Be Your Girl Lyrics

Lyric discussion by batsinger 

Cover art for I'll Be Your Girl lyrics by Decemberists, The

I interpret this song as a shot at the myth of the "friend zone."

The narrator is a guy affirming that he will always be happy to be the woman's friend, even if it never leads to her reciprocating his feelings, and he wants to show her the kind of unconditional emotional support for her that women usually only get from female friends.