# that is not even permitted among the pagans

"that not even the Gentiles permit". This chapter deals with sexual immorality of one church member. Paul now specifically states how the Corinthian believers are proud of their acceptance of that man and his sin. 

# A man has his father's wife

"A man among you is committing adultery with his father's wife"

# father's wife

the wife of his father, but probably not his own mother