Taylor Swift Performs 'Hot in Herre' With Nelly and Haim in St. Louis

— -- Taylor Swift continued her tradition of inviting guest artists to perform on her "1989" tour by bringing out Haim and Nelly for a "hot" performance at her St. Louis concert last night.

After singing "The Fix" with the rapper, the "Shake It Off" singer invited the "Days Are Gone" girl group on stage to join Nelly and Swift in a rendition of the rapper's 2002 hit "Hot in Herre."

Haim has been performing as an opening act on Swift's "1989" tour, and Tuesday night was the band's last show for the rest of Swift's tour dates.

Swift tweeted, "What a way to end @HAIMtheband's run on the 1989 Tour," while including pictures from the "Fix It" and "Hot in Herre" performances.

The "Blank Space" singer also tweeted videos from the "Hot in Herre" performance, describing the synchronized dance routine with Haim as the "highlight" of their friendship.

The Haim sisters tweeted their excitement about the performance last night, noting that they resembled "Charlie's Angels" in their matching white outfits.

Nelly also posted videos of the performances on Instagram, describing the show as "Cray," and calling Swift and the Haim sisters the "cutest background singers" he's ever had.

The North American leg of Swift’s "1989" tour continues through the end of October, after which she’ll head overseas.