Ariana Grande: 18 senior secretive party lover virgin Justin Bieber: 18 senior bad ass not a virgin player Ariana left for a whole year and a half. But no one knew why. Was it because her ex, Jai, cheated on her? Was it because her family was going through a rough time and she was done with it? Or was it because her best friend, Alexa, was dying from cancer? When Ariana comes back it's during the second semester of her senior year. But everybody was shocked when she came back because everybody thought she was gone for good. But the biggest questions were why did she come back and why did she leave? To find out read the story!!!