This note is found in some editions of the NIV:
The words men who have sex with men translate two Greek words that refer to the passive and active participants in homosexual acts.
Some translations appear to be rendering the two Gk words as a single Eg concept, presumably because it could be conceived as a single Gk thought. The KJV tried to represent the two words in two ways: one a
word, the other by
expression. The NKJ has made a similar effort, only by using two different Eg words for the two Gk words.