The 'Facemelt' singer made a pit stop at the fast food joint after partying up a storm while watching Prince perform at KOKO in Camden earlier that evening.
And while most opt for an effortless, casual ensemble when heading to a gig, Rita certainly upped the ante in a floor-trailing deep purple frock covered in sequin embellishment.
Her red carpet-worthy gown was actually a designer buy from Gucci, so we're hoping she didn't spill any ketchup on it!
But unfortunately for Rita she's not the first to step out in the head-turning dress. Transformers actress Rosie Huntington-Whiteley sported it way back in November last year when she stepped out at the LACMA: Art and Film Gala in Los Angeles.
We have to admit we weren't too keen when we first spotted the frock on Rosie - its shapeless silhouette seemed to drown her slender figure.
Both starlets rocked their frocks in totally different ways, with Rita adding a black lace bra and multiple layered necklaces, plus tousled hair and a red pout.
Rosie, on the other hand, went bra-free and kept accessories to a minimum, sweeping her blonde locks back and dosing up on bronzer.
We're pretty surprised to see these two in a style stand-off, but Rita wins our vote thanks to her rock chick accessories. We just can't believe she dared to wear such a luxe outfit to Maccy D's!
Who do you think looked best? Let us know below!
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