Being Honest About Our Motivations
There is no better way to destroy my trust in you than to lie to me about your motivations. It's canon polyamory that healthy relationships require trust. Trust is built by behaving in a trustworthy manner. The best way to build trust is to tell the truth even when lying is ostensibly in your best interest. One the most common ways to do this is when asked about your motivations.
Asking someone about their motivation is a metaphorical trust fall. Because motivations occur only in our minds, there is no way to independently confirm what someone tells us. Unless their actions are so dramatically inconsistently with what they say that it's obvious, it's nearly impossible to tell when someone isn't being honest. A person's word is very nearly all we have to go on.
When someone asks you why you did something, they are showing vulnerability. They are trusting you to tell them the truth. Abusing that trust is a great way to show someone that you can't be trusted in the future.
In my motte-and-bailey post, I talked a bit about motivations:
Human motivation is complicated, and there are often multiple reasons motivating us for a single action or position. Often, when examining our motivations, we will seize on the most palatable motivation and ignore the others.... The only real solution is to rigorously examine and communicate our motivations, which can be incredibly demanding and difficult. It’s not easy to sort out your primary motivation from numerous contenders. The key question is this: but for your stated reason, would you be comfortable with the behavior at issue? ...If you would still object, then your stated reason is not your actual reason.
This is all still true. Often, our motivations will be unknown even to ourselves. And that's fine! "I don't know" is a perfectly acceptable answer, when someone asks why you did something. "I don't want to talk about it" is likewise a perfectly acceptable answer. There's nothing about being honest which requires you to give people information that you don't have or that you don't want to give.
Even if you think you know your motivation, have some epistemic humility about it. Understand that motivation is complicated, and if your apparent motivation sounds a little too noble, maybe take a second look. If someone points out to you that your words and actions don't line up, consider that you may be mistaken. Ask yourself whether, if your stated motivation changed, your behavior would change. If the answer isn't an unequivocal "yes," then there are other motivations at play that should be discussed.
Trust is most important when it's easiest to violate. Lying about our internal thoughts is one of the easiest and least verifiable ways to violate someone's trust. If you value honesty, then value it when it counts.