By 'monogamy', I don't mean simply choosing to have only one partner, I mean the agreement that you won't develop a sexual and/or romantic relationship with other people on condition that your partner do the same ; blackmailing your partner to not act on feelings they might have for other people with the threat of terminating your relationship with them if they do. If you truly loved someone, you would want them to be happy, correct? If developing a sexual and/or romantic relationship with other people would make them happy, how can you say that you love them yet disapprove of something that would make them happy? Most people will proudly admit to being 'selfish', to wanting to keep their partner to themselves, I think this is possessive and objectifying. The world would be a lot better if love and sexual desire were no longer inhibited. Most people want variety (in their sex/romantic lives) whether they act on it or not. I've said before that I think there are two kinds of love : selfless love(empathy) and selfish love (attachment). I think healthy relationships are based on empathy.