A thing that happens when a relationship ends, is that you have no control over the words that your former person uses when talking about you, and the relationship.
It is true that the narratives of a relationship will be different to a degree depending on individual perspective. That’s expected. The problem is when the stories of a relationship are skewed from person to person so drastically, that they cannot both (or all) possibly be true.
Throw polyamory/non-monogamy into this mix, particularly inside small communities, and the misinformation that can be spread among partners, ex-partners, metamours, potential partners, etc. is damaging and sometimes hurtful.
Be mindful of your words.