I lubed up and forced my cock into his tight teen ass. It gave some resistance, but not too much - less than I was expecting. He obviously hadn't had anything that thick up there before, because his facial expressions were all contorted. His butt sure did look beautiful though as he backed up onto my pole. This guy has some potential after all! I flipped him over to loosen him up more, and that worked like a charm. Pretty soon he was ready to ride. Turns out this resident is quite the athlete.