the captain is god on the plane and if you cannot abide by what he directs you to do your only other alternatives are to stand yourself down from the sector or report the captain. both options can be dire so make sure you are not in the wrong. by standing yourself down the captain also knows that he, along with you, will be off for a meeting with the chief pilot and cabin manager. this can, sometimes, cause a rethink by the captain. think very very carefully before trying this