VIDEO : Paulina Rubio Joins 'Little Sis' Demi Lovato on Stage

Demi Lovato and Paulina Rubio met on the show and in 2013, and have remained friends every since. The 45-year-old singer refers to Demi as her "little sister." So it was only fitting that before the 24-year-old singer takes a break in 2017, that she'd invited Rubio to take the stage during her stop at the mother of two's hometown.