Katy Perry in Miami Beach, Florida on July 27, 2012. Credit: INFphoto.com

For her afternoon spent poolside Friday, Katy Perry rocked an itsy-bitsy, teeny-weeny, yellow polka -- er, tie-dye bikini.

On vacation with pals in Miami, the pop star, 27, flaunted her amazing curves in a strapless black-and-yellow two-piece. See more pictures here. Perry accessorized her swimsuit with oversized black sunglasses and a long, silver pendant necklace from Jewels by Dunn.

One day earlier, Perry went with a classic, super-sexy black bikini to hang out with her friends and check out the new issue of Blackbook magazine, which features Robert Pattinson on its cover. (In the interview, conducted pre-cheating scandal, Pattinson discusses the rumors he plans to wed Kristen Stewart!)

Since splitting from ex-husband Russell Brand earlier this year, the "Part of Me" singer has been making the most of single life. In addition to casually dating Florence and the Machine rocker Robert Ackroyd, she's also been enjoying nights out in Los Angeles with John Mayer.

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On June 19, Perry and Mayer spent the evening together at Soho House in West Hollywood. Says an onlooker, "They were affectionate, holding hands and cuddling!"