Everyone knows who Justin Bieber is, right? Not quite. But when director Tyler Perry admitted his ignorance, Janet Jackson was on hand to fill him in on Bieber fever. And while promoting their new film, "Why Did I Get Married Too?," Jackson had some thoughts to share about the newest pop superstars on the scene.

"Who's Justin Bieber?" Perry asked. Jackson, slightly surprised by Perry's answer, explained that Bieber is from Atlanta and is "one of Usher's kids."

Perry then mentioned Jackson's love for Lady Gaga. "I really love Gaga, yeah, and she's a sweetheart," Jackson agreed, saying she was particularly pleased to see Gaga's lovable side because, "it's not always the case when you meet them. You can enjoy their work, but it's not always such a — so pleasant when you get to know their personality, and she truly is a sweetheart."

"Sweet" might not be the first word you'd use to describe Gaga's performances and fashion, but Jackson was still packed with praise for Gaga's unconventional style. "She's definitely doing something different and I love that."

The sole negative thing Jackson had to say about Gaga is actually a compliment. "She works so hard, and I told her, I think she needs to slow down just a little bit, take some time out for herself," Jackson recalled.

Would you want to see a Janet Jackson/ Lady Gaga collaboration? Talk about your favorite pop divas in the comments!

Check out everything we've got on "Tyler Perry's Why Did I Get Married Too?"

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