Katy Perry and Lady Gaga have a rocky history together — not only was it rumored that they asked to be seated as far apart as possible at the Grammy Awards, but they also released their new singles on the same day, sparking even more rumors of competition. While Gaga has claimed that she really likes Katy and her fans, it seems like her feelings may have changed.
The "Applause" singer recently posted a Tweet that definitely seemed to throw shade Katy's way. Click through to see what she wrote, then continue clicking to see more celebrities who dissed other stars on Twitter. Whose diss do you think was the worst? Let us know in the comments below!