Richard: "You'll have to take over all of your sister's duties, including in bed!"

Why do you have to take your sister's place? It's because your sister ran away abroad with her boyfriend. your brother-in-law Richard is angry, he is a millionaire businessman and you are required to take your sister's place as long as his anger has not subsided. you are being used as a revenge while you can't fight back because your college is funded by Richard.