I wouldn't justify cheating because everybody is doing it. A chap who cheats doesn't want the other chaps doing it because if they don't he's the only one left for women to cheat with.
Why do you think stags and buffaloes fight other males off? Females are natural cheaters to an extent that it's not really a fault at all. Hence all the beauty products, fashions and generally putting it about. I think it is a product of evolutionary design which we personify and symbolise in the Adam and Eve story.
The exercise of enchantment seems to me to be irresistible to those females who are confident of their powers.
It's another "last, rasping gasp of the mantis's groom" job. Assuming there is no counter-veiling morality strong enough to neutralise it or at least tone it down a bit.