I want to know if this is a RARE occurence or what?
Personally speaking, No. My wife is totally trustworthy. In my years as an elder, I saw it happen often enough , though.In our immediate family it has certainly happened. Over the years I saw several cases including one where two families were ruined when the wife took a much younger lover from within the same congo.
Dont get me wrong, I believe the majority of dubs to be sincere , moral people ,but it certainly does happen on this side of the pond as well. I agree with those who point to a sheltered youth. There is also the thought that this spouse is going to be with you forever unless you do something to change it - and there is only one way to get a divorce that allows you to re marry