Alex + Sierra Win Season 3 of ‘X Factor’

Male-female vocal duo Alex + Sierra, who are a couple in real life,  won the third season of  'X Factor' last night.

Alex Kinsey and Sierra Deaton were favorites throughout the season, last night they performed a slowed down, more intimate version of Mariah Carey's 'All I Want for Christmas Is You.'

Watch Alex + Sierra Perform 'All I Want for Christmas Is You'