He may have a hit with his rendition of 'Santa Claus Is Comin' to Town,' but that doesn't mean Justin Bieber believes it. The 'Under the Mistletoe' singer revealed that his mom denied Kris Kringle's existence -- but with a pretty good reason.

"My mom always told me there wasn't a Santa," Bieber told AOL Music. "This was her logic: She thought if I grew up knowing about Santa then finding out he wasn't real, that it would be like she was lying to me. And then when she told me about God, I maybe wouldn't believe her. So she just wanted to be straight-up and honest with me all the time." But luckily, Bieber was sweet enough not to share his insider info with others. "I didn't tell my friends or ruin it for anyone," he insisted. "I was a good kid!"

While St. Nick wasn't a part of Bieber's holiday cheer, he enjoys the season anyway. His favorite way to celebrate? Kicking back with his kin. "Christmas Eve is when [my mom's side of the family] get together," Bieber said. "It's also my grandma's birthday so everyone gets together and we have a good time. Then Christmas Day I always go with my dad and now with my little brother and little sister so that's always fun. That's what I'll be doing this year, I'll be in Canada with my family."

So, are Bieber's little bro and sis aware of just how famous he is? Not quite. "[My brother] Jaxon doesn't really know," Bieber said. "Jazmyn knows a little bit but she doesn't really know the extent of it. She knows that I sing, she loves my songs and she'll sing along to them -- she's really cute like that." Aww! Even funnier? "She has just now started calling me 'Justin,'" the Biebs revealed, "but for the past year she called me 'Bieber' because that's all she could say. It was like, 'Bieber! Bieber!'" At least it's a sound he's used to hearing from little girls, right?

While we know Bieber will be giving lots of good gifts this year, what about receiving? That was tricky when he was younger. "We played a game on Christmas Day where everyone brought a girl gift and a boy gift," Bieber said. "You roll the dice and if you get doubles, you get to pick a present and if you don't, it's the next person's turn. Then, the next time you roll doubles you get to choose someone else's present and switch." He continued, "One time I really wanted a Game Boy but I ended up with pots and pans, which was disappointing. I think I gave them to my mom."