Taylor Swift has told Selena Gomez to blast Justin Bieber on her next album.

The "I Knew You Were Trouble" hitmaker is notorious for writing about her previous relationships, and she has reportedly told her best friend to write about the "Beauty and a Beat" hitmaker in an effort to get over him.

a "Taylor's been encouraging Selena got write down her feelings and emotions, and record," a source said.

Justin and the Spring Breakers actress have had a difficult on/off romance, and it is said they split again last month.

Throughout this tough time, Taylor is said to have stood by her friend - and there's eve a chance they could collaborate on Selena's album. "Taylor's had Selena's back through all this. I wouldn't be surprised if they recorded together," the insider said.

The pair have discussed their close friendship in the past, and the blonde singer claimed it was their "longevity" which has made them so comfortable. "It's been the longest one [friendship] I think either of us had really. When your life changes and you become thrust into this really strange whirlwind where what your life is is different from what other people think your life is. And your life is commented on and your life is written about and fictionalized and all that. Both of us have kind of stuck it out and hung in there through all the different changes we've gone through. Longevity is something you really can find very precious and rare in friendships," Taylor said.