Burn down,
Maybe the Captain is not as confident in your abilities as you are.
I have no issue with an FO, one who I know I can trust, disconnecting the auto pilot in the right conditions. I have seen one too many FO's disconnecting the AP and completely f***k it up. Flying the line is no place for show boating, especially in busy airspace. If you want your kicks flying go and hire a Cessna for the weekend.