Kaitlin Marie Gomez, sister to Selena Marie Gomez, finds out that her own boyfriend is cheating on her. Cody, Kaitlin's boyfriend, has some other feelings for Selena. Selena also has feelings for Cody, but she's dating Justin. What will happen when Kaitlin and Justin meet and get along from the start? Will Selena and Cody get caught, or will they play each others lovers to be with one another? Find out in 'Selena's Sister.'