A little bit of help

A kind human boy was walking late in the night when he stumbles on a blind vampire, dying on the ground. Unable
To resist helping one in need he gives him some of his own blood.
The when the vampire wakes up he's Stubborn and unable to accept help from a meet human boy, he tries to leave but discovers his can't due his blindness.
As he is taken care of he begins to fall for the human boy. But how is that possible?