X Factor 2013: Who Is Alex & Sierra? Watch All Performances
Credit: Ray Mickshaw/©2013 Fox Broadcasting Co.    

The X Factor

X Factor 2013: Who Is Alex & Sierra? Watch All Performances

If Jason Mraz and Colbie Caillat were actually dating — and partial to revamping famous pop songs — they might be half as cute as The X Factor 2013's Alex & Sierra. (Speaking of famous duos, there's another pairing that Alex & Sierra remind us of...)

Alex Kinsey and Sierra Deaton, both 22 years old, first met on a beach where Alex was playing guitar in the back of a truck (sounds like the idea for a great first music video). Friends first, Alex would often encourage Sierra to join him during his gigs. Eventually, they realized the kind of magic they had — both on and off stage.

The two officially started dating in 2011, and eventually decided to test the strength of their act by auditioning for X Factor. They picked the show for two reasons: First, they could audition as a duo and second, they'd get feedback from their music industry idol, Simon Cowell.

"We both have really wanted to work with Simon," Sierra told Wetpaint Entertainment during an exclusive interview. "We always wanted to sing for him just because he is so honest. It's kind of intimidating but, you know, if we're not good, we wanted to hear from him that we weren't good."

Simon said exactly the opposite about Alex & Sierra's sexy take on Britney Spears's hit number, "Toxic," during auditions. Their obvious chemistry and their clear musical talent made them an easy pick for the judge who did admit when he first saw them come on stage, "I thought they were going to be terrible."

Alex & Sierra got even more support from the typically unimpressed Englishman during their Four Chair Challenge rendition of the classic Grease number, "You're The One That I Want." Simon aimed to amp up their onstage charm by assigning the pair Robin Thicke's "Blurred Lines."

Although the performance didn't sell all the judges on Alex & Sierra, Simon had no problem putting them through to the Top 13. There they continued to make their mentor proud with their sexy spin on Marvin Gaye's "Heard It Through the Grapevine" and, when that tech glitch happened and the Top 13 had to prove their worth again, with an equally sexy take on Ed Sheeran's "Give Me Love."

Bad set design may have thrown a monkey wrench in their plan's, however. During the Top 12 performances, not all of the judges were taken with the couple's "Addicted to Love" by Robert Palmer. We loved it but was America as addicted? Um, of course! Alex & Sierra looked to redeem themselves the next week with their Top 10 performance of One Direction's "Best Song Ever," a fitting choice seeing as 1D performs the same week as guest stars.

The dynamic duo made it through and for the Top 8's evening of Big Band pre-Thanksgiving festivities they took a cue from Taylor Swift with "I Knew You Were Trouble." What do you think? Are the show's star couple in trouble?

As if. Alex & Sierra rocketed into the Top 6 where they took on one of Destiny's Child's hits, "Say My Name," with Kelly Rowland herself right there in the audience! Kelly was totally impressed, however.

To keep their footing at the head of the pack, the duo both played instruments (Alex brought along his guitar and Sierra was on the piano) for "Say Something" by A Great Big World. We'll say something: Welcome to the semifinals, Alex & Sierra! They're officially in the Top 4 as of the December 5 result show. Congrats, you guys!

As for the semis, Alex & Sierra first sang Of Monsters and Men "Little Talks" as chosen by us, America! It was strong though Sierra's standout moment of the evening came when she and Alex faced off with Carlito Olivero with "Falling Slowly." Speaking of falling, the couple's very next song — Sara Bareilles's "Gravity" — had us falling even more in love with them.

The love continued with the Top 3 where Alex & Sierra first performed Ed Sheeran's "Give Me Love." Then they were joined by special guest star Leona Lewis for a rendition of her hit "Bleeding Love." To finish up the night, the duo returned to their hit version of A Great Big World's "Say Something." Did you love it just as much the second time around?

It sure seems like it since Alex & Sierra went on to win the whole show on December 19! Congratulations, you two.

Watch Alex & Sierra's audition — Britney Spears's "Toxic"

Four Chair Challenge: Alex & Sierra Sing "You're The One That I Want"

Top 16: Alex & Sierra Sing Robin Thicke's "Blurred Lines"

Top 13: Alex & Sierra Sing Marvin Gaye's "Heard It Through the Grapevine"

Save Me Song: Alex & Sierra Sing Ed Sheeran's "Give Me Love"

Top 12: Alex & Sierra Sing Robert Palmer's "Addicted to Love"

Top 10: Alex & Sierra Sings One Direction's "Best Song Ever"

Top 8: Alex & Sierra Sing Taylor Swift's "I Knew You Were Trouble"

Top 6 Diva Song: Alex & Sierra Sings Destiny’s Child's "Say My Name"

Top 6 Unplugged Song: Alex & Sierra Sings A Great Big World's "Say Something"

Top 4 First Song: Alex & Sierra Sings Of Monsters and Men's "Little Talks"

Top 4 Second Song: Carlito Olivero and Alex & Sierra Sing Glen Hansard and Markéta Irglová's "Falling Slowly"

Top 4 Third Song: Alex & Sierra Sings Sara Bareilles's "Gravity"

Top 3 First Song: Alex & Sierra Sings Ed Sheeran's "Give Me Love"

Top 3 Second Song: Alex & Sierra and Leona Lewis Sing "Bleeding Love"

Top 3 Third Song: Alex & Sierra Sings A Great Big World's "Say Something"

Elisabeth Kramer is an Assistant Editor at Wetpaint Entertainment and our resident Downton Abbey expert. Follow her on Twitter and Google+!