Someone who can't help being everyone's friend, and has to be...everyone's friend. They do this to network, make connections, always have a place to stay, and never bedisliked.
Check out the movie 'The World's Fastest Indian' with Anthony Hopkins. From befriending 10 year old boys, to transvestites, to randy grandmas, this guy can't help himself! Makes zero enemies, just several dozen loyal (and generous) friends.
Also think Bill Clinton on his path to be President. Now that we all know we were duped into thinking he was this loveable nice guy, his new name is 'slick-willie', or friendslut.
A friendslut is a person who permits any likely interested person to befriend them. For Example, a straight femaie who allows any random guy to befriend her is a straight-up friendslut.
Goose, you knowyour Mom was a total friendslut because she'd let any sorry-ass guys hang around her during college. Those poor bastards thought they had a chance the whole time.
Friendlationship(n) is a combination of the words 'friends' and 'relationship', used to describe a somewhat-platonic relationship that contains all the aspects of an actual romantic relationship, without any physical/sexual benefits. Basically, all the sacrifice but none of the gain. Often occurs when both people involved harbor some desire for the other, but neither is willing to take a chance and potentially ruin their friendship.