The 16-year-old singer got in trouble with the authorities when he was younger after he and his friend snuck outside in the middle of the night, not realising there was a curfew in the area.
He said: "I snuck out once. My friend slept over and we were like, `Let`s go out.` We just went biking and were being stupid but we weren`t doing anything bad.
"But the police saw us and brought me back home, because there was a curfew on the area! It was two in the morning and I got grounded for a month! That`s the worse trouble I`ve ever been in."
Now he`s famous, the `Baby` hitmaker always tries to be on his best behaviour but admits it`s not always easy.
He told Top of the Pops magazine: "Well, I try not to be rude, but people push and push you. I was at this photo shoot and these guys were like, `Put this on, it looks really cool,` and I was like, `I don`t really like that, I don`t wanna wear that.` This is me, I wear a hoodie, I`m just easy."