this is pretty complicated in my opinion. and I'll be honest I haven't figured this out yet. there's so many factors going on here:
1) looks or personality? can't have both?
2) women (wives, gfs) get old and lose their attractiveness while men still want to have sex with pretty young women.
3) men have an instinct to have kids
4) men need a "reliable" "mate" (wife?) to bring up kids with
5) have an ugly but reliable and good personality wife and have sex with hot mistresses? that's cheating, no?
6) where does "love" figure into all of this?
7) viability of the institution of marriage
I think people are struggling with all of these at the same time and as a result some kind of real life approaches morph - and they're often far from what people would open admit to or discuss.
It's hard to cut out the bullshit and get to the truth on this issue. I'm kind of overwhelmed to be honest.
it seems no one wanted to reply to this. it's too complicated too multi-faceted. it's much easier to make blanket statements one way or the other or argue against them which is pretty much what's been happening in this thread so far.