My clinic partner came up with a delightful hypothetical and I just had to share:
You are happily married and faithful to your spouse. S/he is also faithful to you. You discover that your spouse has a supernatural ability to heal people suffering from incurable, terminal diseases. Your spouse is the only one in the world with this power. The only way your spouse can cure the disease if if s/he has sex with the terminally ill patient.
Would you be okay with your spouse using his/her "healing powers?"
So says Artsy Fartsy at 30.11.06