I had a western civ instructor who talked about homosexuality amongst the Romans, and how a common perception was that men could do everything better, which of course led to the belief that no one could do the deed like another man.
I think its interesting, because when compared to current (American) culture it seems on the surface to be progressive, the whole accepting of homosexuality thing. On the other hand its misogynistic. I think its a cool place to start for an adventure with a complicated social issue, if you have pretty liberal players.
Obviously not for everyone. I know its a little off topic, but its what came to mind.