Catfight! Lady Gaga vs. Kelly Osbourne

After a long history of sparring, Lady Gaga's tense relationship with Kelly Osbourne recently came to a head! When the singer tried to reach out to Kelly on her birthday, the gesture wasn't well received, to say the least. "Not to be ungrateful but why would you send me a birthday cake via my mother?" Kelly tweeted and followed up with more scathing tweets. Lady Gaga responded calmly, saying, "It was meant as a peace offering. Happy Birthday." Kelly later apologized for overreacting. "Life is too short," she said. "I'm glad the feud is over."