Service members are subject to being unfairly punished and even removed from service due to an ambiguously worded rule concerning the act of Adultery, as described in Article 134 in the UCMJ.
This Article has been abused in such a way as to punish Soldiers who haven't even cheated on their spouses, many times without probable cause. In some cases even used against victims of sexual assault (male and female) who spoke up against their attackers.
What consenting adults do behind closed doors, while not always tasteful, is none of the military's business. Marriage is deeply personal and not the military's place to govern.
In no other realm of American society does a person lose their job for making such a dumb decision. We The People are beyond such petty things in this day and age.