I don't think it's as dire, nor as name88 makes it look like but lets' go to the begining... MC went on a date with Josy, Tommy is her step-brother and while he's a douche, and a twat, he could really care about his step-sister, and when MC was checking her out, Tommy was in the house and he did see that. After a drug session with Quinn he ranted about a twerp roaming around his sister, Quinn being different from what we know about, contacted Maya, who despite the whole magna cum laude thing instead of going to an Ivy League university, went to the place her dumb brother Derek went to, and offered her the chance to get a full scholarship if Maya managed to steal away MC's heart from Josy (it would make sesne with what Maya thought about during the grindng session "if only he was.... not in love with another girl"). That would also explain why Quinn interrupted their making session, it would go too fast to be a guarantee that Josy was replaced, so Quinn has to play the devil. and also why Quinn had to say 'I got this' when Sage wasn't convinced about things. and why she said to Camilla that she doesn't have to do it, when MC was spying on them (keep in mind that she was alerted by Tommy)
I know it's a crazy theory but it doesn't conflict too much with other things in the story. And keep in mind that Camilla is a pledging HOT yet she was already on the menu and doing the cumpetition, so probably she was plan B in case MC didn't have any chemistry with Maya