If you agree to something, stick to it. I would go with "If it doesn't work, change it for next time." That builds integrity and trust. I agree that this is going REALLY fast and I would wonder if he needs you to slow down and thinks this is how to do it. Treating you like a child and grounding you is disrespectful I think. If you agreed then I would wonder if you are disrespecting yourself. Talking about feelings and ideas on how to make poly work in your life should bring you to some agreements/boundaries that work for both of you. I would be considerate, responsible and respect each others pace. You might want to do a search in the tags on "boundaries" to see if there is anything in other threads that helps.
Anyone want to be friends on Facebook?
Send me your name via PM