Man this is a huge subject that has no ends story wise. All I can say is I have several friends (at least 3 couples) that were married in the 20 to 30 year range where one of the persons just suddenly/all of a sudden asked for a divorce... no cheating, no explanation, nothing, just wanted to move on, even though the marriage seemed great to the person surprised when hit with the divorce papers/announcement. So anytime I hear someone say "my husband/wife would never leave me, I know them" it makes me think that no one should EVER think that way. Including me.

Best of luck to them both, hopefully they both find peace and happiness.