The 17-year old, who has been dating Gomez since March, admitted to New! magazine: "I wouldn't be with somebody if I wasn't in love."
"Everybody can see she is hot and that's great, but there is so much more to her than that. She makes me laugh and she puts up with my practical jokes."
He added: "We were both raised by our mums in single-parent households, and that's given us a lot of the same family values in life."
The U Smile singer then claimed that despite their hectic work schedules, himself and Selena try to make time to do "normal things" together.
Justin and the Wizards Of Waverly Place actress also hit the headlines last week, after they performed Selena's track Who Says, at Biebs' show in Rio de Janerio, Brazil.
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