Get ready to break out your backwards oversized gear again, because '90s pint-sized rap duo Kris Kross are all growed up and ready to jump jump back into the spotlight.

It's been 21 years since Chris "Mac Daddy" Kelly and Chris "Daddy Mac" Smith became famous for those ridiculous outfits -- and their monster hit "Jump" -- and they've just announced they are reuniting for a 20th anniversary all-star concert honoring So So Def Recordings in Atlanta next month.

While a lot may have changed since the guys last had a hit, one thing has stayed the same ... Mac Daddy is still rockin' the backwards jeans.

'Cause inside out is wiggity wiggity wiggity wack.