Before KUWTK's release in late 2007, the 41-year-old featured in Noughties band Fallout Boy's music video for their song 'Thnks Fr Th Mmrs'.
In the 2007 video, Kardashian can be seen leaning in to give band member Pete Wentz a kiss, while dressed in a lingerie-like embellished look.
While the video was shared to YouTube almost 15 years ago, the star's fans have only just noticed the woman flirting in the video with the band's bassist is in fact Kardashian.