Ashley Tisdale and Julianne Hough spent their Saturday afternoon out riding jet skis in Miami. Julianne's brother Derek was along for the fun, and he went shirtless while wearing just his swimsuit. It seems Julianne has been able to enjoy many hours away from the set during her stay in Florida working on Rock of Ages — there's been plenty of Julianne Hough bikini time between her visits to the pool and beach! Ashley has likewise been getting good use out of her two-piece collection this Summer, including during a getaway to Mexico and her birthday celebrations in Las Vegas. Ashley's trip to Florida was so that she could see her boyfriend Scott Speer, who's shooting Step Up 4 there. She followed up the day on the water by meeting up with Scott for an Italian dinner. Julianne, meanwhile, was busy yesterday checking out a screening of her other new movie, Footloose. The dance film is out in October, and she got her brother and Rock of Ages buddies like Adam Shankman and Diego Boneta together to check out an advance cut.