Oh, gawd. I shouldn't be posting to this thread - blame the cheap sherry I've been reduced to drinking (Thanks, Aldi )
All that guff you've read, about the evolutionary peremptive for MEN to spread their spunk around, comes from Victorian theorists who went a bit overboard due to the simultaneous discoveries of sperm & evolution ... and were Victorians, who thought ladies don't like sex while men do [rolls eyes]
The very few, statistically sound, studies that have been done on the subject (so far) have indicated that women are more likely to 'stray' in search of genetically superior sperm donors! If you stick with evolution theory, this makes total sense because of the massively greater female investment in children. Acting purely on genetic code, you're far more likely to keep seeking a fresher, better inseminator than to stick with the first one you thought was OK.
If the above doesn't sound right to you, stick it in your cultural pipe & smoke it for a while - you know it makes sense
Having said that, most apes (not all) live in tribal family groups and we are apes. There is a strong incentive to keep a family together, as we trust our family members and look out for each other. This affects males as much as females. Each gender is likely to be tempted away from the family tribe by another, if they have attractive qualities.
Since most (not all) tribal apes live in male-dominated families, the boss male is actually the least likely to stray, as he's well sorted for food & love (and has loads of children to protect), while harem members and non-dominant males might well find their offers are better elsewhere
Summary: If you really believe your partner would never be unfaithful (nor would you), you might be right. We are a more evolved species of ape, with free will and a conscious conscience. But, if you believe men are "programmed" to be unfaithful - you're also right, and maybe you need to recognise that you're even more programmed that way!
Ahhh. Got my Pendant fix for tonight! Thanks!