Gen 6: 1-4 indicates they did reproduce with humans.
Not to get this far off topic, but the “Sons of God” and the “daughters of men”- show me anywhere else in the scripture that the “sons of God” are defined as demons?
“Sons of God” - God did not “beget” any other son than the LORD Jesus Christ, to so state is blasphemy against the Christ. And that was via the power of the Holy Spirit, not sexual reproduction. So you are saying that “sons of God are demons, and that they had the same power to overshadow or sexually mate womankind to produce offspring. Hmm. So, God and therefore Christ is behind the power curve in this mystery?
From word study it seems that the difficulty in understanding the “sons of God” and “daughters of men” stems from the account of Cain leaving the community of his family and moving away in banishment, creating a godless culture, and then those outcasts dealing with godly men later in the account.
Indeed, it states the “sons of God” knew the “daughters of men”.
I have no problem with that at all. it is the leap to assume that the sons of god in this text actually means outcast fallen angels/demons who were created, not begotten and therefore not sons at all.