Pop icon Lady Gaga publicly called out Perez Hilton on Twitter Sunday afternoon for what she claims is a stalking attempt.

The incident began when a user alerted Lady Gaga to seeing Perez Hilton outside of her apartment. “This is EXTREMELY EXTREMELY important,” Gaga said to the Twitter user when she wanted to know if Perez was legitimately at her home.

Minutes later Gaga seemingly called her doorman to check. “I have confirmation from the building he was there,” she wrote to the Twitter user.

At the same time she sent the following tweet to Hilton:

Gaga was understandably frustrated by the situation and sent out another tweet, but this time to no one directly:

As of the time of this writing Gaga hadn’t received a response back from Hilton on Twitter. There’s no indication whether or not he reached out to the singer behind the scenes.

The confrontation comes on the heels of Hilton pointing out on Facebook that Gaga’s single has already slipped from the top of the iTunes Music Chart, where Katy Perry’s “Roar” still sits at number one and “Applause” is down to number seven. That remark from the blogger led Gaga’s fans to attack him online. Gaga noticed the situation and told fans to ignore him.

Gaga is currently in New York City to release her music video for “Applause” on Good Morning America on Monday. Hilton is currently visiting Manhattan for an unknown reason.

The two Hollywood power players were good friends during Gaga’s Fame era. Pictured above is a photo of the two together during that time.