During the Sunday performance of her "Enigma" residency in Las Vegas, the superstar musician and actress referred to the breakup before singing the classic love song "Someone to Watch Over Me," E! News reports.
"Last time I sang this song I had a ring on my finger," she told the crowd. "So it will be different this time."
A fan shared footage of the emotional moment on Twitter. In the short clip, Gaga is seen walking across the stage and flashing her ringless finger to the crowd.
Gaga and Carino revealed in February that they'd called off their engagement after two years of dating.
The news came just a few days before Gaga, who'd been racking up prizes for her "A Star Is Born" performance, attended the 2019 Academy Awards ceremony, where her song "Shallow" won an Oscar for best original song.
She also neglected to mention the 49-year-old talent agent in her heartfelt speech after "Shallow" won a Grammy.
Gaga was previously engaged to actor Taylor Kinney before calling it quits in 2016.
Since her split with Carino, the "Born this Way" singer has been busy with her Vegas residency, and on March 12 she revealed on Twitter that she's working on a new album.
“Rumors I’m pregnant? Yeah, I’m pregnant with #LG6,” joked the star.