I really hate to say this, but is there any evidence that the late wife would not have wanted sex with her husband? I know young people tend to think us olds have no interest in woohooing or worse, that it is disgusting if we woohoo, but that is a form of ageism. Certainly, nursing homes would rather not have to deal with people in their care engaging in woohoo, as it creates difficulty for them, so certainly are biased against the practice. However, if we are going to be so hyper protective as a society as to make it the default that old people can reach the point that they won't be allowed to woohoo with those they were woohooing with, then we should be able to have documents similar to a living will detailing who we want to be able to woohoo with once we are legally unable to give consent.
There is no grey area here, if a person is not mentally capable of consent, there is no debate to be had.
Then you're condemning that person to being cut off from what for most people is a significant part of their life. You're condemning them to being a living corpse unable to fully partake of life's pleasures. Frankly, if as a society we decide to condemn them to involuntary celibacy in such circumstances, then I would consider such a status a valid reason to allow the person to have decided ahead of time that if they ever do permanently reach such a state, they'd rather be euthanized.
If you have advanced Alzheimer's or some other state of severe mental impairment, you basically are a living corpse. Sorry, but when you can no longer reason or communicate with others, you have ceased being human and started simply being a hunk of flesh that happens to be able to convert oxygen into carbon dioxide. The person you were before - the person your spouse married - is gone.
There would be more dignity and humanity in that guy just going and having sex with a prostitute than using his wife like some piece of meat to satisfy his own carnal needs.
