When Julianne Hough went on “Lip Sync Battle” she stunned the audience in more ways than one

In May 2015, actress and dancer Julianne Hough faced off against her brother, dancer Derek Hough, in one of the best “Lip Sync Battle” episodes ever.

After bringing the heat with a performance of “I Just Had Sex,” by the Lonely Island, Julianne Hough returned to the stage to perform “All About That Bass,” by Meghan Trainor.

Since the song is about the singer’s butt, Hough performed some of the song with her back…er…butt to the audience, which she made sure to shake at all the right times.

Near the end of the song, Hough was joined by Trainor herself, who took over singing, and showed Hough how to shake her “bass” in the appropriate manner.