'DWTS' Switch-Up Week Preview: Who's Dancing With Who, Plus Who's Returning to Guest Judge! (PHOTOS)

Just as we're finally getting used to the couples and picking our favorites on Season 21, "Dancing With The Stars" hits us with Switch-Up Week! On Monday night's episode, the week we've all been waiting for is finally here as we get to see the nine remaining couples true potential as they dance with a different partner for the night.

As a relatively new twist, only starting a few seasons ago, it's one of the most anticipated twists of the show. Seeing the stars dance with different pros lets us see just how well they adapt to change and just how comfortable they are on the dance floor.

It's always fun to see as their actual partners watch them dance with their new partners. Most of the time, it turns out to be a pretty positive experience as they learn new things, but sometimes, it can completely mess them up as all the pros have their own way of teaching.

"I'm excited and terrified," Vine star Hayes Grier told People of the switch-up, and that seems to be how everyone feels going into this week's show. 

Here are the pairings and dances, which fans helped pick, for Switch-Up Week, which airs Monday October 12 on ABC:

Andy Grammer and Nick Carter's partner Sharna Burgess - Argentine Tango

Bindi Irwin and Tamar Braxton's partner Val Chmerkovskiy - Cha Cha

Alek Skarlatos and Hayes Grier's partner Emma Slater - Rumba

Carlos PenaVega and Alek Skarlatos' partner Lindsay Arnold - Quickstep

Hayes Grier and Andy Grammer's partner Allison Holker - Viennese Waltz

Alexa PenaVega and Bindi Irwin's Derek Hough - Tango

Paula Deen and Alexa PenaVega's partner Mark Ballas - Jive

Nick Carter and Carlos PenaVega's partner Witney Carson - Paso Doble

Tamar Braxton and Paula Deen's partner Louis Van Amstel - Samba

Once they dance their dances with their "switch-up" partner, which can really shake up the competition, they will return to their original partner's next week. 

As if the switch-ups aren't exciting enough, former "DWTS" pro, and popular bad boy, Maksim Chmerkovskiy will be returning-only this time, as a guest judge. Val's brother Maks will be judging alongside Carrie Ann Inaba, Bruno Tonioli and Julianna Hough and Chmerkovskiy fans everywhere can barely contain their excitement as the two hotties will finally be back on camera together.

Maks left the show following his big season 18 win with Olympian Meryl Davis, according to Entertainment Tonight. He decided to leave so he could focus on other things. He is also currently dating former pro Peta Murgatroyd, and the two seem extremely happy together.

The stars have been posting a ton of photos to social media as they start to practice with their new partners for the week, and we can already tell it's going to be an awesome show!