Perry, Swift feud over backup dancers

A cold war between singers Taylor Swift and Katy Perry broke out when three of the former's dancers shifted to the latter's troupe a year ago.

Swift continues to hold a grudge over the matter, so much so that she even wrote a song titled "Bad blood".

According to TMZ.com, Swift felt betrayed because she became very close to the dancers and considered them family, but they wanted to work with Perry.

However, the three dancers had actually worked with Perry first, and her tour ended several years ago, they needed work that's when they signed up as dancers during Swift's tour.

The three dancers told Swift they can't be on her full tour and asked for a 30-day out with the intent that they could join Perry on her tour. But Swift became so upset that she fired the trio.