Hi there. Thanks for the opportunity to revisit these points. The canonical NT is not always a self-defining document, or else it would not have words that appear only once. For points of comparison between words we also have the Septuagint, and as I note, the Wisdom of Solomon is a particularly important reference for Romans 1, as Paul all but glosses it.
So, yes, we know that angels are often called ‘men’ (cf. also Judges 13:6), but the allusion in Romans 1:27 is to the special vocabulary for gender that is happening in Genesis 1:27 LXX. Something about created order, about the rankings and relationships between heaven & earth, is involved.
In the same way the men also abandoned natural relations with women and were inflamed with (orexei- hunger) for one another. Men committed shameful acts with other men, and received in themselves the due penalty for their error.
In the reading I advance, this is happening: In a way that extends the pattern of idolatry, ‘men’ are not having physical sex; instead, appetite is happening. The meaning is: There is consumption rather than reproduction.
The end of that pattern could only be death, annihilation. It is destruction without creation.
The Nephilim died out, and that radiates to the more important drama of the death of their fathers, the Sons of God/Watchers. This is the Enoch/Qumran storyline of which Christianity had no conception. Rome thought Romans was a sex-ed manual.
As we are ‘one in Christ’, as we are ‘one body’ (1 Corinthians 12:12–27), there is no distribution of gender happening between spirit being expressed in biological terms. We are one in Christ. He is the male, we the female.