1Co 5:1 It is reported commonly that there is fornication among you, and such fornication (porneia) as is *not so much as named* among the Gentiles, that one should have his father's wife. (KJV)
1. "Every literal use of porneia is prostitution or illicit sex between single persons."
Therefore Sharon concludes the woman was the son's stepmother:
Quote from Sharon: The son was committing fornication (porneia), and “the kind [toiaute] of fornication” is relations with his stepmother. "
Sharon further concludes that in order for the sexual activity between the son and his father's wife to be "fornication" the father must also be dead.
Quote: The stepmother is most likely a widow,
According to Sharon - the son was having sexual relations with his dead fathers widow (stepmother - not his birth mother). Which means that the situation was that two single (unrelated) people were having sexual relations. (fornication) By making these assumptions Sharon is able to believe that the stepmother and son were committing fornication according to her pre-suppositon that only single persons can commit fornication.
To make this conclusion Sharon adds two elements to the situation that are not in evidence in the text.
1. The Father is dead. (Not in evidence)
2. The woman is NOT his birth mother (Otherwise it would be incest)
The problem is that if Sharon's view is the actual situation then we must also believe that in pagan Corinth "even among the Gentiles" such sexual activity between two unmarried people " was so untolerated that "it was not even named."
I have a problem concluding that the sexual activity that was so terrible that even among the gentiles it was not spoken of - was simple sexual intercourse (fornication/porneia) between two unrelated single people.
As I understand it the Corinthian culture was so evil that they had sex with everybody - without much regard for race, religion or gender. However, if the sexual activity between the "son and his father's wife" was actually the son *openly* having sex with his birth mother (his living father's wife) - that indeed might raise a few eyebrows - even in jaded Corinth this open incest was not tolerated.
When viewed in that context - Paul's statement can be taken quite literally without having to add things not in evidence to the text.
1Co 5:1 It is actually reported that there is sexual immorality among you, and of a kind that is not tolerated even among pagans, for a man has his father's wife. (ESV)