I also think it's about someone with bulimia,
"I can taste the blood on your lips and on your tongue" - He's kissed someone who has just made herself throw up which resulted in her throat bleeding
"The less and less I eat the more you see my teeth" - The more weight he loses the happier he is, so he's smiling more
"Rip the flesh from your bones" - Again, wanting to lose weight
"you'll need all those fingers for crossing" - Rather than using them to be sick
Could be wrong though, but i do adore this song :)
I also think it's about someone with bulimia, "I can taste the blood on your lips and on your tongue" - He's kissed someone who has just made herself throw up which resulted in her throat bleeding "The less and less I eat the more you see my teeth" - The more weight he loses the happier he is, so he's smiling more "Rip the flesh from your bones" - Again, wanting to lose weight "you'll need all those fingers for crossing" - Rather than using them to be sick
Could be wrong though, but i do adore this song :)