Justin Bieber's the latest celebrity to wade in to Kanye West's feud with Taylor Swift.
It's after he posted a screenshot of his FaceTime phonecall with Kanye to Instagram, captioning the photo with the words: Taylor Swift what up.
The photo, which also features their manager, Scooter Braun.
Fans were quick to see Justin's post as a dig at Taylor, which led to the hashtag #TaylorSwiftWhatUp trending worldwide on Twitter.
It all started with Kanye West's controversial lyrics about Taylor Swift in his song Famous.
This is how Taylor respond a few weeks back on her instagram: