Marry
"only if the affair is discovered. And it seems that most aren't."
I agree. I knew someone, long before children but deeply in love with exh at the time, who seemingly had the perfect relationship. They were just a loving and happy couple. But he and I were talking one night (drunk talk in the pub), and he confessed he had affairs because although he loved his wife dearly, they weren't having sexual relations. I told him he would have no luck with me and he seemed most disappointed - the cheek of it!
Also after exh and I separated I was feeling the need for the love of a man, horny (!), so went on an affair site. I was staggered at the number of men registered on there, close to my area (almost 6,000 out of a population of 30,000 men roughly). My libido disappeared pdq, and I got the hell out of there, it just reeked of desperation. One man put himself down as a deeply committed Christian, who was very sad not to be having sex anymore. I still get the shivers thinking about it.