Very good posts and opinions, all. They got me all keyed up to give my two cents :

The marriage to Apollonia just didn't ring true with me, and I thought Coppola would have omitted it from the film. However, I have to agree with Turnbull that it was probably necessary cinematically. Someone Michael cared about HAD to be killed in Sicily when Michael was the target. If the victim were, say, Don Tomassino, the dramatic impact wouldn't be the same. It had to be a spouse, since that would set the stage for Michael's shift toward wanting to be Don. The double loss of Sonny and Apollonia awakened this coldness in him that called for vengeance and retribution.

It still kind of jars with Michael's previous relationship with Kay and his character, though, especially when you consider the rest of GF1 and all of GF2.

At the end of GF2, we see Michael alone, having lost everything he cared about. That's the main message we're meant to take away with us, and it would lose impact if Kay were someone he married only out of expediency. Family was a cornerstone to him. His family was not just his children, it was his wife too -- the whole family unit. It is notable that in that final image, Michael's left hand is resting against his face, showing very clearly that he is still wearing his wedding ring. If Kay were not the love of his life, then I think the poignancy of that image would suffer.

JustMe, I enjoyed reading your post (we're like-minded about GF3 ). But I do believe that the Michael in the novel is a rather one-dimensional character whom Coppola made more complex on the screen (in GF1 and GF2, that is). That is why I don't think the "book Michael" is a good source for how the "film Michael" felt about Kay, how he felt about love, or how he felt about sex. (If it were, then Coppola would have kept all those details about him in the film; but instead, he changed them.) Yes, he lied to Kay, and the person he became drove her away; but he thought he was doing all he did to protect his family and to keep them close to him. I was touched by many scenes in GF1 and GF2 where Michael is very tender with Kay and their son.

I'm still looking forward to more opinions on why Michael didn't remarry after GF2 . And BTW, I think he loved Kay very much. And another BTW: Did anyone notice if he was wearing his wedding ring in GF3?