Don't be too harsh on your friend just yet! My eldest son found it hard at first when his younger brother came out as gay many years ago.
For some, its a euphemistic slap in the face but after a while, logic can break through and they see that nothing has changed, bar the fact that they know one more little thing about you. It may be that he doesn't come round to accepting, but then quite sincerely, what will you have really lost? Hurtful yes, but life goes on.
Rebecca