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Before Fifth Harmony took to the stage at our iHeartRadio Jingle Ball hosted by Z100 on Friday (December 11), bandmate Camila Cabello surprised fans for a collaborative performance alongside Shawn Mendes of their new duet "I Know What You Did Last Summer." 

Sure, Shawn performed numbers like "Stitches," "Something Big" and even a few bars from Eminem's "Lose Yourself" during the latter, but the real highlight came during the collaborative number with the 5H member. After performing "Never Be Alone," the arena went absolutely black and lit up with Camila standing right besides Shawn, who is totally just a friend, in case you were wondering. It was like pop star magic right in front of our eyes. 

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If you missed out on all the action, consider this your holiday gift. You'll be able to relive the night on The CW during a special 90-minute broadcast on December 25th and 30th at 8 p.m. ET/PT -- so put on your Santa hats, grab some gingerbread cookies, and tune in!

Photo: Getty Images