Old Sew'n'Sew
All Strings Considered
Yes this sort of union is not possible Jesus spoke these words above to show that the obedient angels do not marry even each other in heaven, but, throughout the Bible angels were given assignments to deliver messages and help righteous people on earth. In order to do that they would have to materialize a human body to carry out their mission. Some examples would be; when the men/ 'angels' came to Sodom and Gomorrah and led Lot out of the district ( Genesis 9:1-11 the crowds around Lots house wanted the men/ 'angels' so that they could have intercouse with them. ), another one is; Abraham fed them a meal and they told him Sarah would have a child, also Jacob wrestled with a materialized angel all night to get a blessing from him and was lame for the rest of his life from that encounter.
An angel appeared to Manoah and told him how to raise his son Sampson, and Manoah didn't know he was an angel til he ascended in the fire of the offering, and many more.
So do you think it is possible for some of the Angels to misuse this ability to materialize human bodies without permission from God, and do something not allowed by God? Yes.
The bodies that they materialized were human therefore they could use them to take wives and have children. Again, this was a perversion and a sin on their part, because you are correct that Angels are not supposed to marry or dwell on earth. (There are similar things going on today among mankind such as same s_x marriage.)
In 1 Peter 3:19,20 thats exactly what it says; "By which also he went and preached unto the spirits in prison; Which sometime were disobedient, when once the long suffering of God waited in the days of Noah, while the ark was preparing, wherein few, that is, eight souls were saved by water." KJV
and also Jude 6 "And the angels which kept not their first estate, but left there own habitation, he hath reserved in everlasting chains under darkness unto the judjment of the great day.KJV
2 Peter 2:4 "Certainly if God did not hold back from punishing the angels that sinned, but, by throwing them into Tar′ta‧rus, delivered them to pits of dense darkness to be reserved for judgment;" NWT
This seems to indicate that they are greatly restricted, unable again to materialize as they did prior to the Flood.
It is even possible that the Greek Mythology was based on the exploits of these "men of fame"; distorted memories passed down for centuries. Many of the myths have the Gods marrying human women, and their offspring performing superhuman feats of strength, think Hercules.
Still researching 
But I love to look for things like this. I think that 'living' fossils are interesting,.......
