Why Cats Headbutt
Q: Why does my cat headbutt me?
A: When a cat "headbutts" or rubs you with the back of his or her head, this is called "bunting". This is the way cats truly show affection.
Your cat may tend to do this, especially along your nose and chin. This is from the behavior your cat exhibited with the mother cat when seeking to nurse.
When your cat rubs against you with it's body, it is simply marking you with his/her scent and claiming you as "theirs" but a "headbutt" is true kitty affection.
I guess it's true, Love Hurts.