Some men are just that way..regardless of how blessed be their wife to them, and happy be their marriage, they are yet attracted to the whole sick thrill of infidelity.
As for these women well they may very well enjoy the whole no strings attached benefits that come with having a married lover,or they might be after the challenge. Whatever be the reason ultimately it takes two hands to clap. And a woman after married men will sooner or later get what she deserves as will the unfaithful spouse..and it won't be so thrilling then!