Interesting, and probably a radical lecture in some people's eyes, by Christopher Ryan. It's about monogamy and the history of our species from a sexual standpoint. Christopher argues that the current Victorian norm of relationship and sexuality is a relatively recent phenomena of humans and maybe we aren't at all made for monogamy.
We have appetites. I think it was Schopenhauer who said, a person can do what they want but not want what they want. And so what I'm arguing against is the shame that's associated with desires. It's the idea that if you love your husband or wife but you still are attracted to other people, there's something wrong with you, there's something wrong with your marriage, something wrong with your partner. I think a lot of families are fractured by unrealistic expectations that are based upon this false vision of human sexuality.