The people who seem most afraid of monogamy not being socially enforced are Jordan Peterson and his type. They are afraid of anything where male supremacy might be upended, so yes, that also includes others like conservative religious folks who are also hghly invested in hierarchy and control of women. Social enforcement comes about by looking sideways at and judging anyone who has another type of relationship dynamic - saying that they are immoral, can't commit, don't know how to love, etc. Monogamy is so deeply entrenched in our culture that even many relationship therapists think this way about polyamory, because they don't actually know anything about it.

Your wife is no doubt a product of growing up in this same culture. Thanks for your comment and I totally agree, people really ought to mind their own business about how others live and love when it's not hurting anyone else.