Katy Perry took the stage during Rock in Rio 2015 in Brazil on Sunday -- where she brought one very lucky and seemingly intoxicated fan to the stage during her performance. The entire exchange was pretty strange, to say the least, as the young KatyCat (who's been identified as Rayane) couldn't help herself from kissing Perry's neck, hands and grabbing at her waist. "I think she’s rolling," Katy announced to the crowd, after asking someone backstage to bring the poor girl some water. Nevertheless, the "Firework" singer handled her handsy devotee like a champ ... and even had a little fun with her while she was up there. "How do you say 'hello' in Portuguese?" Katy asked. "Olá!" Rayane shouted. "How do you say 'pizza'?" Katy inquired. "Pizza!" Rayane hilariously responded ... after rubbing her face on Katy’s costume. Judging from the video, this girl might not even remember meeting Perry!