Cheaters are reprehensible at any age, but 45 years of marriage puts an image of a 60-something woman cheating on her husband into my head. Yech. Yes, I am apparently ageist, but the idea of a wrinkly post-menopause *affair* raises not only moral, but also physical hackles for me. I am not trying to say that people in their 60s should give up on sex, but when it is in a long-term committed relationship, there is more than lust there, I think. In an affair, that's just lust, and I can't see anything to lust for in a 60-something person without love.
Takes you out of the pool in the over 50's club when the proportion of women to men increases and leaves more for the rest of us who are not dried up prunes with blinders on but who are formally attached to sticks in the mud or might-as-well-be-dead mates.
P.S. I turn 64 next week.