Thoughts and feelings are private/ours but actions are public and I like to have a plan if I'm going to act differently than I usually do in a situation. Thinking and talking about not leaving does not hurt me or anyone else but acting on it can hurt both the person acting and the person on the receiving end of the action. If we're in someone else's space at their invitation, outstaying our welcome is an aggressive boundary crossing at the very least and does not get us anything.

It's a little like a child crying when they don't get what they ask for and having a tantrum; if they were "good" and polite and made the request later in the day, pointing out how they had been cooperative and gone along with the program a long time that day, they might have reason to expect getting a "reward" or what they asked for, getting their "turn" in the relationship. It's a two-way street but insisting on more than our share or not fulfilling our portion of the "contract" does not get us anything we might possibly want?