I invited J to be a family with our iPhones, sharing apps and tunes. He ignored me for about 3 months, and then sent an invitation to be in HIS family. I said, "woohoo!" because the inviter has the credit card for the shared purchases. (There is an approval process if one choses to invoke it)

Except he never added the confirmation code for his credit card and now I can't buy anything unless I leave the family.