I'm poly because I have NEVER loved only one person at a time and because I am fortunate enough to have fallen in love only with people who can't understand why they would need to limit the sources of my happiness by keeping me all to themself.
My first real relationship (now my fiance
) has been open from the start. I explained to H that I loved them very much and wanted them to be happy and, for me, wanting H to be happy is not the same as wanting to *make* H happy. I want to maximise H's happiness and my own and we agreed that monogamy was something that wouldn't do that. H has their eye on another guy and I love watching them with him and seeing him make them happy.
My two girlfriends C and E feel similarly and are not jealous of H or of each other.
I'm poly because I can love many people and do so without hurting anyone and can also make my lovers happy.