Although, we don't exactly know the reason behind the feud, we do know it got a lot more heated over the weekend. It all started because Perez Hilton was reportedly shopping for a new pad in NYC and one of the places he looked was Gaga's building. Fans notified Gaga and called Perez a stalker. Perez is saying otherwise though and since issued a public statement.
Click here to see what Perez had to say about the whole thing.