...."the word (porneia) refers to “prostitution, unchastity, fornication, of every kind of unlawful sexual intercourse.” This would include homosexuality'...

That's the point! Exactly! 

'Unlawful' sexual intercourse would even include the use of a contraceptives, or spouusal 'rape' without consent. If we include all those things there aren't many marriages that could not be divorced, annulled, and re-marriage allowed.

Using "no divorce", Period. as the rule is not considering the full Gospel, nor 1 Corinthians.