We know that there's no love lost between Katy Perry and Taylor Swift.
The full history is a long and complex story, but in short, Taylor and Katy fell out in a big way after Katy allegedly hired Taylor's dancers in the middle of Taylor's tour. In an interview with Rolling Stone, Taylor said the experience made her realise they were "straight-up enemies", and she reportedly wrote the track "Bad Blood" about it.
Most recently, Katy Perry weighed in on the ~drama~ between Taylor Swift and Nicki Minaj.
Following Taylor's tweet to Nicki in which she called her out for "pitting women against each other", Katy Perry shared a comment of her own.
@NICKIMINAJ I've done nothing but love & support you. It's unlike you to pit women against each other. Maybe one of the men took your slot..
She took to Twitter to share this not-so-cryptic opinion, which was widely seen as a dig at Taylor.
Finding it ironic to parade the pit women against other women argument about as one unmeasurably capitalizes on the take down of a woman...
The tweet referred to Taylor's song "Bad Blood", which is rumoured to be about her fallout with Katy. The track was released as a single, and Taylor enlisted most of her female celebrity friends to star in the video.
After Taylor apologised to Nicki and Nicki forgave her, everyone assumed everything would go back to normal.
But then during one of Taylor's performances on her 1989 world tour, a shark was brought out for her rendition of "Bad Bloodβ.
@TSwiftOnTour @TSwiftNZ @taylorswift13 THERE WAS A SHARK DURING #BADBLOOD TODAY #BADBLOODSHARK
Many people took this to be a reference to Katy Perry's now infamous performance at the Super Bowl, where a backing dancer dressed as a shark forgot the choreography and the "Left Shark" meme was born.