The sons of God, are Elohim. And this is plainly evident in a variety of places in the old testament. Not just in Enoch.
Who said anything about marriage?
Job 38:7 NASB1995
[7] When the morning stars sang together And all the sons of God shouted for joy?
Here the sons of God are directly paralleled with morning stars. This is a common title of elohim or angels.
Job 1:6 NIV
[6] One day the angels came to present themselves before the Lord, and Satan also came with them.
Job 1:6 ESV
[6] Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them.
Here's another example, you can see I've used two different translations to point this out, in Hebrew it's bene Elohim, sons of God. But you see some translations just simply say "angels". And here they are meeting in the heavens, and Satan is among them.
The sons of God are angels. This is established in Biblical hermeneutics and studies of the dead sea scrolls. This isn't debatable.
Maybe people just haven't read their Bibles close enough before to know that the sons of God are translated as "angels" in an assortment of translations, they're in passages that directly parallel them with angelic objects like stars, they are referenced in an assortment of passages that further link them to angels.
That's just what they are. Hence why many translations simply call them "angels" even when the Hebrew plainly says bene Elohim or "sons of God".
Here is another example:
Psalms 29:1 NIV
[1] Ascribe to the Lord, you heavenly beings, ascribe to the Lord glory and strength.
Psalms 29:1 NABRE
[1] A psalm of David. Give to the Lord, you sons of God, give to the Lord glory and might;
Psalms 29:1 CEV
[1] All you angels in heaven,honor the glory and powerof the Lord!
In Hebrew, that is bene Elohim. Here it is translated as "heavenly beings" or angels, depending on the translation.