You: I think I'm gonna do this, so that you can have alone time.
Me: I don't really need alone time. I'd rather you stay with me.
You: Well, I already told (other person) that I was going to.
I know you don't like to cancel things. So why say 'I think' when what you really mean is 'I am?' Why present it as an idea for discussion, when it doesn't matter what I say about it? And, if it does matter, why would you tell me after it can't be changed?
I accept fully that you don't need my permission to do things. I know and like which of us has control. What sucks is when it seems like you're talking to me, when really you're just telling me. What hurts is when it feels like you're letting me stand, and then the rug is pulled from under me. I don't mind kneeling. Being thrown to the ground unexpectedly isn't cool.
I think sometimes we make decisions thinking we know what's in the best interest of others who are involved. And it misleads us into thinking that the decision we made is right because we're so sure about what the outcome will be.
I completely know how you feel because I've been there but I also know that I'm guilty of doing this very thing to the people I love most.