“…and they called to Lot and said to him, “Where are the men who came to you tonight? Bring them out to us that we may have relations with them.”” Gen. 19:5
Although more liberal sources would argue that the phrase “have relations with them” is not necessarily sexual in nature, the Hebrew word used, ידע yada`, is the same word used in Genesis 4:1 “Now the man had relations with his wife Eve…”.
Apparently the idea of men copulating with angels taking on the form of men is so coarse that it tends to overtake the whole of the story. Though homosexuality is forbidden in the Levitical law (see Lev. 18:22 and 20:13), it is not the point of the narrative here, and it is not necessarily the sin that is causing destruction to soon come upon Sodom. According to the prophet Ezekiel, it is seemingly more benign sins; “arrogance, abundant food and careless ease” (Ezek. 16:49). Jude 1:7 in the New Testament reinforces the immorality shown by this act, but we would do well to be on guard against the “seemingly more benign” sins, lest we don’t get the whole lesson from the story.
This narrative does evoke a brief theme from Genesis 6, where the “sons of God came in to the daughters of men” (Gen. 6:4). To those that hold the interpretation that angels were copulating with human women in the time before the flood, this theme too can become overpowering – often I’ve heard people say that God had to flood the earth because of the Nephilim, however it is clear that God brought the judgment of the flood due to the wickedness of mankind (Gen. 6:5-7; 11-13; 17).
Interestingly, Jude 1:6 may be referencing this story when he refers to “angels who did not keep their proper domain…”.