John Mayer put a ring on single lady Katy Perry , but it's not an official engagement bauble.

Katy was spotted wearing the stunning heart shaped ring as she and Mayer left L.A.'s Vicenti restaurant on Valentine's Day, and she couldn't have looked happier.

PHOTO: John Mayer Out And About

Mayer purchased the ring from Santa Barbara's high end jewelry designer Daniel Gibbings.

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