Lyric discussion by christchin910 

Cover art for Funeral Dress lyrics by William Fitzsimmons

My interpretation is quite different than you guys.

What I got out of it is a man and woman are best friends, and the man wants to be more than friends. The woman kind of does too, but has a boyfriend. The man waits and waits for them to break up, but decides it hurts too much investing time into something that isn't going to work at the time. So, he can't wait for her, as the song says.