Cara Delevingne Shnoystering Sienna Miller ... Which MIGHT Be Hot???

TMZ TV

Just when we thought Cara Delevingne had moved on from Michelle Rodriguez ... and picked up with Sienna Miller -- CD dropped a "SHONYSTER" bomb.

Yeah, the word was a mystery to us too ... but now that we've figured out it has nothing to do with oyster shucking, clam digging, or any kind of seafood ... we're kinda bummed.

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