steepholm

But as mentioned earlier, there is no precedent in my society for banning first-cousin marriage, nor would it occur to me that it was my "business"; if one were to interfere, cousins could offer the same "not planning to breed" defence that you suggest, and then do so accidentally; and in any case, even if one were to ban such a marriage, there would be nothing to stop them having sex and children outside marriage. One could offer medical advice to all of these categories of people, whatever their marital status; I don't perceive a right to do more, in either case. (I speak as the daughter of an elderly father; in my family, large age-gaps between partners have been very common.)