Let's get into this a little bit.
"Sons of God" - Same Hebrew term used used again only in Job as a clear reference to Angels.
Job 1:6 New King James Version (NKJV)
Satan Attacks Job’s Character
6 Now there was a day when the sons of God came to present themselves before the Lord, and [a
]Satan also came among them.
Job 38:7 New King James Version (NKJV)
7 When the morning stars sang together,
And all the sons of God shouted for joy?
it would be ludicrous to think that the "sons of Seth" were there at the Creation of the World.
Jude, the Lord's half brother, identifies these beings specifically as Angels, and ties their punishment to the sexual sin they committed. They left their 1st estate, or habitation.
Jude 6 New King James Version (NKJV)
6 And the angels who did not keep their [a
]proper domain, but left their own abode, He has reserved in everlasting chains under darkness for the judgment of the great day;
The Greek word is "oiketerion". The only other use of this word is here:
2 Corinthians 5:2 New King James Version (NKJV)
2 For in this we groan, earnestly desiring to be clothed with our [a
]habitation which is from heaven,
As you can see, this is a clear reference to the Heavenly body we will receive. The ANGELS that fell LEFT these bodies, and mated with human women. THAT'S THE REASON THEY ARE IN CHAINS IN PRISON!
Angels can take on EARTHLY bodies, in HUMAN form. It doesn't make them human. The Angels cannot mate IN HEAVEN. There is no disagreement about that.
How does a human son of Seth, mate with a human son of Cain, and produce a super human giant? Unless we want to completely allegorize ALL the Giants in Scripture now.