This is a story as related to me by a white acquaintance. For the sake of narrative simplicity, I’m going to give the characters completely made-up names.
Anne had worked for several years in an office, (I don’t recall specifically what profession, but something white-collar,) where she had happily befriended several co-workers. One of these co-workers happened to be a black woman, Betty.
One day, Anne happened to overhear Betty and another black co-worker, in the breakroom, discussing interracial friendship.
“White people never have black friends,” said Betty. “Every time I hear a white person claim they have a black friend, I know they’re a racist.” The other co-worker agreed.
Anne went home and cried.
Had her friend never thought they were friends? How could anyone take her friendship as proof of racism?
White people want to have black friends; it lets them prove to themselves (and others) just how non-racist they are. It makes them feel better about themselves and assuages some portion of guilt. To have a black friend makes a white person feel like a good white person.
(As emotions go, guilt seems does not seem to function very logically.)
Black people, by contrast, have no particular desire to prove how non-racist they are.
I suspect that many black people find it really annoying when whites try too hard to befriend them.