In that culture, anal sex was something that one did with slaves. The encounters between adult men and boys apparently were seen as romantic, but not did not generally include certain activities.
I still have trouble believing that the boys did not come out with what we'd consider emotional scars from the experience, but I'll readily believe that they came out with less scarring than a boy in our culture who had the same experience would be expected to have from it.
Cheers,
Ben