In our society we are indoctrinated from birth that our wife will be loyal and faithful and supportive.
Doesn't matter how smart you are, indoctrination nearly always wins.
Only experience allows us to break free, they will be unfaithful, they will asset strip you, they will bear false witness against you, they will deny you access to your children, NONE are different, it's in their genetic programming. Only fear of extreme punishment (or lack of opportunity) will stop this.
Allowing it to happen a second time is what sorts smart from stupid!
In Muslim countries where women gain nothing from divorce, and death from cheating, there is neither divorce nor cheating.