My daddy always said there is book learnin and common sense and extentions of each or the fact that one can?

Single people can't have affairs. How can they be happy? All they can have is dates. Affairs are much more exciting than dates. People get married so they can have affairs.

Sex with your husband wouldn't be an affair, that's called marital relations. What most people call common sense quite often leads to error, especially in a technological society like ours. The days when formal education was something people could get by without are long gone, the unemployment rate makes that abundantly clear. Even "common sense" should tell you that without a job you won't have much of a life, and someone who can't read can hardly fill out a job application.

You can't have an affair with your husband, you're married to him. I think Letterman's a bore.

I really don't think that what consenting adults do in private is any business of the public at large. In other words, why don't you mind your own business.