How does that old song go, again? "If you're happy and you know it, wear a t-shirt that says "HAPPY" across your chest." Teenage dream, Katy Perry was spotted arriving back at her hotel in London last night after a shoot for UK show Chatty Man. The "California Gurl" was immediately surrounded by a of British fans and gladly obliged them by signing autographs. Flip through to the the "Peacock" songbird grinning from ear to ear at the warm welcome.