Your comments on Sodom and hospitality are spot on! Hospitality is a big issue in the East and it is interesting to note that the basis for judgment when Jesus returns is hospitality or lack thereof(Matt. 25: 31ff).
A similar but seldom mentioned story is in Judges 19. The men of the city want to treat the stranger in a similar way to that of the men of Sodom. The owner of the house who is showing the stranger hospitality offers his daughter and the stranger's concubine instead. The men take the concubine and gang rape her because she is the property of the stranger and to abuse her is to abuse him.