Taylor Swift is full of surprises during her '1989' tour stops and recently she brought Jason Derulo up on stage for the second night of the tour in Washington, DC!

The "Shake It Off" singer seemed to have had a great time with Jason as they performed "Want To Want Me" live, a song that Taylor called her favorite summer jam on Instagram. So awesome!

I got to sing my fav summer JAM 'Want To Want Me' with @jasonderulo in DC- I'm also loving his new single 'Cheyenne'!

A photo posted by Taylor Swift (@taylorswift) on

What do you think of the pics? Are you planning to catch the '1989' tour live? Let us know in the comments!