Why does Kay divorce Michael?

Could you elaborate on the reasons behind Kay's decision to divorce Michael? Were there any specific factors that contributed to this decision, or was it a culmination of various issues? Was there a particular event that served as a catalyst for the divorce proceedings? How did the dynamics of their relationship evolve leading up to this point, and how did it ultimately lead to the dissolution of their marriage? I'm curious to understand the complexities and nuances of their situation that ultimately led to this outcome.