Hi Mustache Pete how are you? Michael betrayed Kay from the time they were dating saying "That's my family, that's not me." at Connie's wedding. He stayed with that same delusional belief that the Corleone family will one day be legitimate. He knew how the game would play out. Yet, he lied to her to convince her to marry him and be the mother of his children. She was quite naive too and trusted him. He betrayed her. He was never straight with her.
I'm good. I hope you're well, too.
I don't think Michael ever knew how the legitimacy game would play out. I think he does probably play out the same scenario in his head over and over through the years, but that no matter what point he wants to reach, he eventually finds out "there just wasn't enough time." For instance, any rational person would react to Tahoe assassination attempt by moving to a sheep ranch in New Zealand or somewhere, but I think Michael's personality looked at it as confirmation of how difficult and dangerous his plan was, so that he had to go even slower, eliminate even more potential enemies.
That's not to say that Michael was all there: he was a psycopath, but I think that he was trustworthy within his little group.
