Lady Gaga Debuts New Video Amid Twitter Feud with Perez Hilton

Lady Gaga debuted the music video for her new single "Applause" on Good Morning America Monday, but the bigger drama was playing out behind the scenes.

Gaga and her former BFF Perez Hilton engaged in a nasty war of words on Twitter over the weekend, with the singer accusing the gossip blogger of stalking her because he was considering buying an apartment in her building, according to The Hollywood Reporter.

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"My heart hurts that my former very good friend Lady Gaga, a person I used to call my 'wifey' and traveled the world with, is making very public and very untrue allegations about me on Twitter," Hilton told THR in a statement. "While it is still too painful for me to go into detail about why I chose to no longer make her a part of my life, I will say that I am a critic and not a stalker. Any allegation that I am stalking her is utterly false, defamatory and now appear to be putting me in danger." 

A source tells THR that Hilton is in the market for a new apartment and had no idea Gaga lived in the building where he was looking.

Gaga has also accused Hilton of sending her a nasty message regarding a hip injury she suffered earlier this year, which incapacitated her for several weeks and forced her to cancel several dates on her "Born This Way Ball" tour. "Still have the text Perez sent me of me in a wheelchair w the words KARMA written across + Madonna pointing a gun at me. Day of my accident," she tweeted.

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Though Lady Gaga subsequently deleted most of her replies to Hilton, several of her fans took matters into their own hands and tweeted threatening messages to the blogger.

"I can't sleep," Hilton tweeted overnight on Sunday. "I am literally sick to my stomach. Not playing any f---ing games here. I am afraid for my f---ing safety and that of my son."

Watch the video for "Applause," the first single off of Lady Gaga's upcoming album ARTPOP, below.