Don't think it's fair to just assume this. Only they know what has happened in their marriage and how it has affected them emotionally.
From what I see though things started to get weird after Honey Nut Cheerios and the birth of Lala Kardashian having her *** and **** out on TV every chance she got
Gotta be extremely hard for your growing son to have to deal with everything that comes with that.
I'm sure Melo always cheated but after that seems like his care for getting caught went flying out the window