I've had similar issues with H requesting schedule changes... Don't negotiate so much. Just make the decisions that you feel are best for you. It doesn't matter if you have plans or not. You are allowed to say, simply, "I'm sorry, I'm not available". It is important to keep in mind that there will be times when you need favors from him... but you can say no.
I'm looking at it as a good incentive to GAL, so that I can say "I'm busy" and mean it!!
