I think this is about a woman who has been through a lot in her past relationships but despite this the man still wants to "follow the footprints across my lovers stomach" and learn all about her past.

The man and the waitress have a special relationship because the man treated his daughter wrong the same way the waitress was treated wrong by her father. the man acts sympathetic towards her because of his guilt and she acts rude ish towards him because of her personal anger towards her father. besides the fact that she doesn't like the bum, she "notices my abscence on the afternoons I don't come."

i think that in the first part he introduces that he's kind of a player but then there's one girl he falls inlove with but can't have because she has a boyfriend but he gives her all the love and everything he has just to see her smile. in the second section he talks about how her boyfriend does her dirt and in the third i think he's kind of deciding that sticking around just digs himself into a bigger hole so he decides to let go hence the "no more sad poems" and how hes considered just a friend so he's gonna grow a backbone and move on.