Just chanced across this article
Martin Sheen boycotted Grace and Frankie scene over 'awful' penis-shaped bucking bronco - News - TV & Radio - The Independent
Martin Sheen objected to doing a particular gay scene, saying he was a "prude", despite being on record as a supporter of gay rights. Fortunately, the director said that "that was his opinion" and got someone else to do it. To me this is a good example of someone running into an ethical dilemma in the moment and exercising their judgment in accordance with their conscience. Clearly the director didn't see it coming and could have said to Mr Sheen - you agreed to do a gay film, what are you complaining about, just get on with it.
Perhaps she could have sued him, saying that she had to go to the trouble and expense of getting a body double, and that he upset her and the gay community with his self-confessed "prudishness". Surely the gay community will be deeply offended by his judgment on them (no difference between activity and person allowed).
Will Mr Sheen now advertise his services more carefully in future, spelling out what kind of gay scenes he won't do because of his squeamishness?
Or does Mr Sheen have more rights to be selective about his work than a baker because he's famous and a supporter of SSM?