Taylor Swift what up: Justin Bieber steps into star's row with Kanye West
Justin Bieber appears to have taunted fellow pop star Taylor Swift with an Instagram picture of him FaceTiming Kanye West.
Wading in to the public feud between West and Swift, t he 22-year-old Canadian singer captioned the image: "Taylor swift what up."
West, 39, is shown grinning alongside two friends as he shares a conversation with Bieber.
Swift, 26, was reportedly not impressed with Bieber's on-off relationship with her close friend Selena Gomez, 24.
Now Bieber has appeared to throw his support behind West.
The feud between Swift and West began in 2009 when he grabbed the microphone while she was accepting an MTV Video Music Award.
The music stars mended their relationship over the following years, but they have recently clashed over the lyrics to his song, Famous.
Famous includes the controversial lyrics: "I feel like me and Taylor might still have sex, Why? I made that bitch famous."
West insisted Swift had given her blessing, while Swift denied she had ever heard it.
Reality star Kim Kardashian, West's wife, later released a video on Snapchat of West on the phone talking about the song.