Second when Michael fled to Sicily after murdering Sollozzo and McCluskey
Michael only contacted Kay after being back longer than a year
Yet Kay still married Michael after all this time? Here -- Kay was calling and writing....
Vito, having no other suitable blood Corleone to succeed him, had Michael under his tutelage [with “Vito's guidance and counsel”] and that's why it took longer than a year for him to get around to seeking Kay and settling for her
