Hi, I'm looking for a story. Despite it being a very long story, I cannot find it back.
Main character takes a sidejob in babysitting some spoiled kid of some millionaire.
Turns out the kid is terribly smart and manipulative; blackmails the main character to work in Mexico to help him build some kind of lab to grow big and muscular.
First try-outs on a test-subject (slum orphan) are very promising, but the test-subject became very dumb. The kid and scientists decide on a slower growth to reduce the loss of iq.
Athletic boyfriend of main character is lured into the plot as well.
Athletic boyfriend grows bigger together with the now bigger and grown older kid. Bf cheats on the main character because of the sudden spike of horniness after the procedure. Kid blackmails the boyfriend to become his sex slave, just to spite the main character.
Big kid now grows even bigger. Locals revolt. His millionaire father finds out and pays the lab an unexpected visit.
It's too late, kid is a huge beast now. Father's own son tries to kill him, but he survives. Main character stabs the beast with a syringe that nullifies the countermeasures against dumbification. Beast roars in pain and escapes.
Main character and his boyfriend are back together. Years later they find the beast, now retarded, in a circus. They're glad that the evil kid can do no harm any more.