Taylor Swift and Justin Bieber are reportedly eager for a collaboration, but for this the 'Shake It Off' singer might require her bestie and Bieber's former lover Selena Gomez's permission and blessings.
A source informed that the 'Love Story' hit-maker would never go behind her 22-year-old singer friend's back and work with 'Baby' singer without Gomez's blessing, Contactmusic reported.
The source added that if any such collaboration between Swift and 21-year-old pop-star takes place then it would have to be under extraordinary conditions.