The centaur looked at Derrick lustily, "So the nymphs made him the most spectacular sex toy you could imagine. Endurance, stamina, durability, and shape-changing flexibility to be come more suited to you... whims. The more you use him, the more perfect he becomes for you."
"What!?!? This is unacceptable! He's only 15! This is illegal! Where are these Nymph whores who had sex with my underage son? I'm going to sue you, and sue this establishment and you'll all be out of a job!" Derrick's dad was terrified and confused but he expressed it as fury as many do.
The centaur blinked slowly rolling his eyes while they were closed, this wasn't the first outburst he dealt with, it won't be the last. "Of course sir. I apologize for the offense we have caused you, I will find those nymphs responsible right away. Why don't you and your family stay in this private room right here while we find those troublesome Nymphs and get everything fixed. Derrick, come spend some time with your family!" as Derrick passed the centaur he whispered, "Show your parents what you learned, then come see me." Derrick smiled eagerly.
Mythological creatures have amazing charisma and can usually get what they want from humans. Humans tend to have significant memory impairment for a good period which is how the resort stays open, and this is more pronounced with more intimate contact. Derrick now qualifies as being somewhat mythical and things were about to get very intimate.
Within minutes Derrick tricked and then seduced his father into an exhaustive and intoxicating series of sexual acts that left him panting and physically unable to do little more than lie there. His mother however was resistant and Derrick looked notably more feminine despite his cock due to interacting with his father.
"Mom, I love you and I'd never do anything to hurt you." Derrick said sincerely, beginning to work his superhuman charms on her. Within a few more minutes Derrick was making out with his mother and after an hour or so Derrick was looking very much like a 25 year old version of his mother's high school star quarterback. Both his parents completely enthralled, and thoroughly exhausted, they rolled together and thanked each other for the surprisingly wonderful time forgetting about Derrick and that he was part of it. Derrick left the room satisfied that he had done a good job and went to find the centaur who called for his services.