Christina Aguilera on stage at the Billboard Music Awards
05/19/2013 at 09:55 PM EDT
's sexy slim-down continues.
coach showed off a slender figure while performing at the Billboard Music Awards in Las Vegas on Sunday.
Wearing a short black Hervé Léger by Max Azria skirt and black top, the singer joined Pitbull for their song "Feel This Moment."
Just last week, Aguilera, 32, gave fans a sneak peek of her scantily clad body when she Tweeted a photo
from the set of a music video.
At the season 4 premiere
of The Voice
in March, Aguilera chose a little black dress that highlighted her changing figure.
A source close to the singer has confirmed Aguilera is working out at home
regularly and "exploring new methods of exercise" with different trainers, including weight training with fitness guru Tee Sorge.