The angels in Genesis 6 did not "marry" anyone. We see the word 'marry' because of the prudish and legalistic attitude of the translators.
Translators could be quite squeamish and shy to say what God will blurt right out and hit the listeners right on the head with.
For example, in Genesis 6:1-2?
It should read if properly translated more like this...
Now it came to pass,
when mankind {literally 'adam - came to be used for 'mankind'}
had begun to 'become numerous'/multiply
on the face of the ground {adamah},
and daughters/'beautiful women' had been born unto them . . .
that the angels
{beni ha Elohiym idiom: literally sons of 'elohiym/gods}
kept watching the daughters of mankind . . .
that they were very beautiful . . .
and they took/'seized passionately' to them women {'ishshah}
{here is a masculine plural suffix signifying 'it happened
but was irregular'}
of all whom they examined and selected.
Young's literal translation also does not use the word "married."
And it cometh to pass that mankind have begun to multiply on the face of the ground,
and daughters have been born to them, and sons of God see the daughters of men that
they [are] fair, and they take to themselves women of all whom they have chosen."
There you have it ....................
Misleading translations induce mislead believers.
This pastor believed that will all his heart, and dedicated his life of ministry to study, study, study, and teach.
https://rbthieme.org/index.html#tabs-3
grace and peace ..................