Can we deal with evidence? Seneca (the Roman historian) says that "bad army officers and wicked tyrants are the main sources of rapes of young men."
I'm doing more reading now. "Accounts of homosexual rape of Roman citizens were favourite themes in contemporary folklore." "Slaves, foreigners, or prostitutes could be used for sexual purposes without constraint." - Mezey & King, Male Victims of Sexual Assault, 115.
So tell me how you "can't see it"—I'm dying to know.