Yeah, if you are a sheep. Non-monogamy has always been an option. if you're in a trusting relationship then all social conditioning should go out the window because now you are dealing with an individual.
If you can't express yourself, own it. It's not on "society", it's on you.
If I'm honest with you and tell you that non-monogamy is not an option for me that is NOT me stigmatizing anything. It's called honesty.
People should probably figure this out before marriage, not 20 years and and start blaming your partner, LoL. Oh, wait, we're on Earth.