Offer Mark to the fraternity
From Create Your Own Story
You go to the leader of the fraternity and tell him about Mark. The guy just smiles and says. "We'll take him but he has to wear only a pair of white sock and some tighty whitis for an event during the party." You agree and he pays you a lot of money. Later on the night of the party you barely convince Mark to go along with it. You can't stop staring at his exposed muscles, his underwear leaving nothing to the imagination.
Then at the party you drag Mark into the house and frat boy pass by snickering. Mark is mortified but you force him to continue on. Inside the party the frat leader guides Mark over to a pole in the center of the party. Then he's handcuffed to the pole and you get ready to watch pulling out your phone to video tape for more blackmail. Almost imidiatly two guys in lettermen's jackets walk up to Mark and start feeling and squizing his muscles. Then one pulls his underwear down to just bellow his butt and the frat boy opens up his own pants to revel his already stiff wood. The other Frat boy then kneels infront of Mark and pulls the new whore's underwear down below his cock. Then the Frat boy on the floor stats to suck on Mark's cock while the 1st one thrust brutally into Mark making him cry out in pain.
The two frat boys continued to use Mark almost fully clothed and so did the many other men used Mark that night. At the end off the party the frats did one last thing to Mark's poor abused body. They pulled out paint buckkets and covered him in paint matching the color of the opposition team and then shoved a large dildo inside his ass leaving it there. All finished with him your roommate collapses to the ground and when you get close he cusses you out. You did say they could do whatever they wanted to him. Once his paint dries you pick Mark up and help him limp out of the party.
At home you tell him to take a shower and he complies. While he dose you consider what to do next.