Watch ​Lady Gaga Bring Bradley Cooper Onstage in Vegas to Perform "Shallow"

Watch ​Lady Gaga Bring Bradley Cooper Onstage in Vegas to Perform "Shallow"
A Star Is Born co-stars Lady Gaga and Bradley Cooper have racked up plenty of awards show recognition (mostly) for their onscreen performances, but the pair hadn't actually performed their hit song "Shallow" live — until Saturday night (January 26).
 
Gaga brought the film's director and male lead out onstage in Las Vegas during her "Enigma" show. They sang the duet live for the first time, with Cooper admitting that he'd never even worn in-ear monitors prior to that night.
 
It's good practice, as the pair is expected to perform "Shallow" at the Oscars on February 24.
 
Watch their onstage reunion in Vegas below.