Does anyone know meaning

Someone I know added this to the bottom of an email. Does anyone know the meaning. "Im your fifteen stone first footer".

Mark

I cant tell you this in a way I feel is not inappropriate. it really depends on who sent it but my experience with it is that it never really means anything good. course I have little experience with the person who sent it and I am not sure how they specifically meant it. they may as well as you not know what it means.