So many relationship structures are out there, reflecting diverse needs, desires and expectations. As a society, we have begun to talk about the fact that not everyone wants to be monogamous and that it might not make everyone happy. However, many have yet to notice that even within monogamy, people are broadening its definition (and shifting its timelines).
When someone says "monogamy," we often think of marriage, kids, the works. And yet, just because someone may prefer to be with one person at a time does not mean they want to be with that person forever.
The term "modern monogamy" is sometimes used to speak to a dynamic where an individual prefers an exclusive partnership with another person but understands relationships as impermanent or seasonal. They have released the notion that one person will be with whom they spend their entire life. Or that this one person will align with who they become in the future or remain compatible with time.
For example, what you want in a partner at 20 may differ from what you want in a partner in your 40s. As you go through life, you may seek different types of support, connection or traits. Sometimes, to remain compatible with someone throughout a lifetime, we stop ourselves from growing and changing.