Rick: He went off on his false belief that angels reproduced.
No one can say for certain that is a false belief - as it may well be correct. Even the footnotes in the ESV Study Bible (widely acknowledged by evangelical scholars as an excellent translation) say that interpretation that asserts these sons of God to be fallen angels is one possibly legitimate view. It notes, in Hebrew, the term Nepilim means "fallen ones."
Even Hugh Ross, in his book, "Navigating Genesis," acknowledges this interpretation may be accurate (
https://reasons.org/explore/publication ... -the-flood).
It is interesting, the juxtapositioning and phrasing in Genesis 6:4, "the sons of God" with "the daughters of man." Why would it need to be specific to note that the daughters were human in context with the odd "sons of God?"
Many try to refute the fallen angels assertion to be wrong based upon Matthew 22:30 - where Jesus says angels do not marry. However, that cannot be used to refute it as Jesus was referring only to angels in Heaven.