Well the fact that he didnt ask and took it behind your back means he is NOT a "very good friend" Im going to use a eminem quote for this.

What are friends?
Friends are people that you think are your friends
But they really your enemies, with secret indentities
and disguises, to hide they true colors
So just when you think you close enough to be brothers
they wanna come back and cut your throat when you ain't lookin
What is money?
Money is what makes a man act funny
Money is the root of all evil
Money'll make them same friends come back around
swearing that they was always down