On Saturday, the 36-year-old "Oops I Did It Again" singer posted an Instagram video of herself wearing an aqua sports bra and tiny pink shorts and doing backflips. The clip only caught fans' attention after they noticed that Timberlake's "I Think She Knows" interlude from his song "LoveStoned" was playing in the back.
"Nothing like flips and Mother Nature!!!" the pop star captioned the quick clip, with fans overjoyed that she would be playing her ex-boyfriend's track.
"Awww to Justin music ! Love you Britney !!! You're a God sent !!!," one follower wrote, while another one added, "She's usin Lovestoned by @justintimberlake I'd love to see them collaborating."
"Love ❤️ your song choice @britneyspears 🙌💪," one fan praised.
Spears and Timberlake first met while starring on The Mickey Mouse Club and years later dated from 1999 to 2002. After their shocking split, Timberlake released "Cry Me A River," which is said to be about Spears cheating on him.
In 2016, Spears said she would be down to collaborate with her ex. Soon rumors began that they were working on new music together. However, a source told ET at the time that no such collaboration was in the works.