> Americans, as I understand it, tend to have “the talk” which is a clear idiom for an actual conversation where they mutually decide to “be exclusive” America

> Americans, as I understand it, tend to have “the talk” which is a clear idiom for an actual conversation where they mutually decide to “be exclusive” American here. Neither I nor, to my knowledge, any of my close friends in relationships have had this "talk" you speak of. In my experience, expectations around monogamy (or not) are not explicit but typically pretty clear from the nature of the relationship.