With Rihanna's reputation for being just a tad raunchy and Emma Watson being the quintessential English rose, you do wonder what they'd have to talk about.
But they obviously found some common ground when they hung out on the set of their new film The Apocalypse in New Orleans yesterday.
The singer and the former Harry Potter star shared a laugh as they took some time out in between filming the-end-of-the-world comedy.
Their style also reflected their good girl/ bad girl images as Rihanna flashed some flesh in denim hotpants and a netted jumper, while Emma was more conservative in jeans and a blazer.
The film is Seth Rogen's directorial debut, and also stars James Franco and his pal Jonah Hill, who Rihanna was spotted filming scenes with.
The plot sees the cast enjoying a house party chez Franco when the world decides it's going to end.
Well, we suppose that's more exciting than someone throwing up on your mum's persian rug then passing out in the bath.
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