You're misinterpreting Tom's and Sonny's relationship. They were like brothers, such was represented in the flashback scene at the end of GFII between Sonny and Michael when Sonny went after Michael.
Michael reveals his feelings about Tom early in the film. He intriduces Tom to Kay in the course of which he tells her his last name. He then tells Kay that Tom is not a Sicilian. Both statements are accurate, but they are also indicative of Michael's lack of comfort with Tom.
I understand what you are saying. So you dont believe that Tom was out of line in how he talked to Sonny? (Just asking :))
I do remember Michael and his comments to Kay about Tom. I just think there is more to it. Michael's hearing testimony paraphrasing here "Godfather is a term used as a sign of respect" etc.
