I've personally prosecuted more than that for adultery. Granted, almost always the affair involves an officer and his/her subordinate, which is the underlying predicate for the prosecution. But, adultery is always one of the specifications charged.
“...almost always the affair involves an officer and his/her subordinate,”
In the cases I mentioned, only one involved fraternization; the others were adulterous relationships with civilians, with another member’s wife, and such.
The Lt Gen was notorious for flying his military aircraft halfway across the country several times a month to meet with his mistress (ostensibly to meet with one of his remote units). It continued until the Maj General I worked for (at the base he flew to), refused to let it go.