Its entirely possible and that's the best I can do without actually knowing you.
I'm more of the opinion these days that monogamy is 95% cultural programming and less about innate biology and psychology than people think. I started my love life being as monogamous in thought and deed as I thought possible. Now...well here I am. Once you start peeling back the layers of the programming the world around you has slathered on, some very interesting things start popping out.
The big lightbulb moment came for me when I got to the concept of ownership and mutual happiness; monogamy is essentially ownership of another person, at its very core. You OWN the other person, they are allowed to give their love to you and only to you otherwise they're a bad person and thus you control them. With mutual happiness, if your partner is happy being with someone else, isn't that a good thing? I mean you love this person, and part of loving someone is wanting them to be happy, so if that person is happy being romantic or intimate with someone else as well as you then isnt that a good thing?
I've had people decry that as martyrdom; it ignores the stress non-monogamy might cause on someone not ready to accept it yet so trying to "guilt" (yes that word has been used before) someone into being non-monogamous before they're ready is encouraging martyr behavior. I personally think that's a step short of unmitigated twaddle; ownership isn't fun regardless of how many people pat you on the head and tell you its ok.
I am as direct as a T-Rex with 'roid rage and about as subtle. It isn't intended to cause upset, I just prefer to talk plain. There are plenty of other people here who do the nice, polite thing much better than I can. I'm what you'd call a "problem dinner guest."