Selena Gomez Flaunts Her Cleavage and Legs in Skimpy Dress

For a performance in Puerto Rico over the weekend, Justin Bieber's girlfriend, 19, shows off a lot of skin in a leg-baring onesie with a wrap-around skirt

Welcome to the onesie club, Selena Gomez!

Last night, the 19-year-old starlet flaunted a whole lot of sexy skin during a performance in Puerto Rico when she took the stage in a superskimpy outfit.

Justin Bieber's girlfriend wore a plunging blue gown that revealed plenty of cleavage, while her maxiskirt wrapped just around her backside, showing off her legs in a bedazzled bodysuit.

"Puerto Rico-- 4 hours til show time," Selena had gushed on Facebook beforehand, "so excited to be back such a fun place to kick off my South American Tour it's like my second home. Love you all."

Last year, the Wizards of Waverly Place star's fellow Disney alum Miley Cyrus also made waves when she performed in some provocative barely-there outfits.

But with a long skirt covering part of her assets and a fairly low-cut bodysuit, is Selena's sexy costume classier compared to Miley's? What do you think of the star's look? Weigh in below!