That's why some people call it a "fog. And that's also because some believe that actions boil down to choices and decisions, and that integrity matters.
All married people took a vow of sorts, with some variant of "For better or worse". There was no caveat that "Hey, but if the 'worse' includes you betraying me, then all bets are off." Or "Gee, you know about that 'worse' part? what I meant was that as long as it does not get too uncomfortable for me that I want out or if it does not fit my idea of what married life should be".
Choices. Decisions. You take a vow, you stand by it. You choose not to, that's also your move. But it's a dangerous, even chaotic, notion to think it's ok to walk out when a "line" is crossed. "I don't love you any more". "You don't take out the garbage like I want you to". "You were playing hide the sausage with my best friend!". In cases of obvious abuse, sure it's udnerstandable, even needed, but how do you draw the line otherwise? Ergo, the issues of entitlement and the "fog".
Me 42 W 39 Married: 11 Jan 1998, T: Since 1992 First Bomb: Sep 2007 Confirmed A/OM: 4 Nov 2007 Kids: D10, S5 Reconciled and together again after (alot of) time and heartbreak. 3rd kid, S, born 2 Jan 2010.