Pity for the Boot Licker?

Narcissist's don't have "friends" they surround themselves with Syc·o·phants and other boot lickers.

/ˈsikəfənt,-ˌfant/

1. a person who acts obsequiously toward someone deemed as important in order to gain an advantage 
2. a servile self-seeking flatterer 

What would you call the people that cling to narcissists despite evidence to suggest that they will be used, exploited and abused?