Made in Chelsea Celebrity Mash Up sees the Channel 4 News presenter attend a toga party as Cheska Hull's 'new man'.
Cheska proudly shows off her date to Binky Felstead and Ollie Locke, but the romance quickly crumbles when Jamie Laing declares his love for Cheska, causing her to run from the party in tears.
Former TOWIE star Childs makes an equally unexpected appearance at the event, as Laing's 'little sister'.
Introduced as an Oxford student who was a member of Mensa at 12 and sat 18 A-levels at 14, Oliver Proudlock and Spencer Matthews are surprised to have never met her before.
"Best-looking book worm I've ever seen. What happened to the family genes? She's tall and attractive and you're you," Matthews comments.
Other celebrities in tonight's episode include Rick Edwards fitting Locke with his first measured suit, and Francis Boulle finally landing an intern worthy of Boulle Enterprises - Nick Hewer of The Apprentice and Countdown fame.
Celebrity Mash Up airs tonight on Channel 4.