It’s getting Hot In Herre! Watch Taylor Swift perform with Nelly and Haim!

Welcome to Nellyville!

Taylor Swift provided backing vocals at her own concert, along with girlband Haim, as they were joined on stage by rapper/singer Nelly to perform his hit *Hot In Herre. *

Last night, Nelly took to the stage at the Scottrade Center in St. Louis for Taylor's 1989 world tour to make the ultimate super group.

Tay-Tay shared her excited - as much as feeding our inner 16-year-old-self - by bringing Nelly on stage and she also shared her glee on social media.

"Old friends. @derrtymo has come out to surprise the crowd on my last 3 tours. I absolutely adore him," the Bad Blood singer told her 48.7 million Instagram followers.

After singing *The Fix *with Nelly, Tay-Tay brought Haim on stage and said: "Are you ready for what's about to happen, will you please welcome Haim onto the stage!"

Then, as Nelly exited the stage the trio sister-band - including Este, Danielle and Alana Haim - sang Forever and Let Me Go to the audience.

Taylor should have also called up her pal Justin Timberlake to perform this golden oldie with Nelly:

Beyonce's 10 BEST holiday pictures: