If a politician is unmarried/separated, I think that what he or she does is his or her own business, as long as it is legal, doesn't harm others, and is reasonably discreet. On the other hand, if a married pol has an affair (or a one-night-stand, for that matter), that is an indication of a basic lack of trustworthiness and I have the old fashioned idea that one should trust one's representatives. On the third hand, that is my opinion, and there are always those who think that everyone's business is theirs.