As previously detailed, it is totally on between Taylor Swift and Katy Perry.
The "Shake It Off" singer took her feud public with
Perry an unnamed artist when she told Rolling Stone that she penned a new song titled "Bad Blood" about a singer who tried to "sabotage" a recent arena tour of hers.
Perry then pretty much confirmed herself as the target of Swift's wrath when she Tweeted about a "Regina George in sheep's clothing" soon after Taylor's remarks went viral.
Amazing Mean Girls reference aside, what is the basis for this beef between pop superstars?
According to TMZ, it boils down to three backup dancers who worked for Perry first... then joined Swift’s tour in 2012... then left Swift's tour once Katy went back on the road.