Safety Friend
A friend who will always be there when everyone else fails. Most of the time not considered a desirable position to be in. Side effects of being a safety friend include being left behind as your friends make new friends and leave, only being called upon when a friend needs to wine or complain, and might also include a life without anyone to trust or keep close.
Alex: Man, I'm tired of all my new friends. They were so "of the moment"

John: Well we always have our safety friends to call on.