That's just it though. Because we as a society have been conditioned by Christian doctrine to only know one woman that people have to hide their other girlfriends, prostitutes, and side chicks so as not to be ridiculed by people who also most likely fantasize and or have multiple partners in their lives. Hypocrisy everywhere.Well, to be fair, most people don't condone having side chicks or mistresses in today's society, even if plenty of people practice that. That's why in most relationships you would want to hide your side chicks from your spouse. Personally, I think society is still far too puritanical in this regard, though there isn't much I can do about it personally haha. Humans weren't really designed to be monogamous, if we were we'd all have tiny little peckers like gorillas, so it's natural for us to want to be with other partners even if we are in love with only one person. Society in general is still very set on us being monogamous for life though.
And I agree with you in that males always want generally more than one partner and remains the same with animals outside of humans as well. Since the beginning of time men, prophets, kings, lords, knights, army hordes have always had more than one woman in their lives. It's biological within us to want more than one woman.