When the people of Sodom surrounded Lot's residence in town at bedtime, it was not just men outside wanting to know whom Lot's guests were. And, "yada," the Hebrew verb for to "know," to "become acquainted with," or to "be introduced to," is used in that context.
Lot had two virgin daughters still at home that night; but, his married daughters were outside with their husbands, Lot's sons-in-law. Their not having known any man had to do with the fact that Daddy Lot had kept his younger daughters at home and now allowed them to have any male aquaintances yet.
Later in the same chapter, Genesis 19, after Lot and his daughter had to flee the Cities of the (Jordan) Plain which were ablaze and his wife had turned into a pillar of salt, and they were up in the high mountains, the two daughters decide that since Lot had no living sons, he had to have grandsons to carry on his name and they thought Daddy was the last man on earth (or at least in the local area). So they decided to get their father drunk and lay with (shakab) him so that they could get pregnant by him. One daughter "slept with" him one night and the other one the 2nd night. "Shakab" is also a Hebrew euphemism for to "have sex with."
In the almost 950 times that "yada" is used in the Hebrew text, only 10 of them have to do with possible sex. And what is in Genesis 19 is not one of them. I believe that if the author of Genesis wanted the "men of Sodom" to have sexual intercourse with Lot's guests, he would have used "shakab" instead of "yada." More than likely the people outside of Lot's door that night really wanted to beat up his guests.
I don't think that until the people at Lot's door were blinded by his guests Lot himself did not know his guests were angels. The people of Sodom never knew the were angels. In every place that the Hebrew or Greek word for angel is mentioned in the Bible and are given a description, they look like adult men. Angels in the Bible do not have wings. Cherubs, aka cherubim, have two wings and Seraphs, aka seraphim, have 6 wings; but, neither of them are called angels. Oh, those same angels are called "men" in Genesis 18.