Good friends Zac Efron and Ashley Tisdale played together on the beach in Malibu, CA, Saturday. It was Ashley's 26th birthday, which she celebrated by basking in the sunshine sporting a sexy bikini with her pals, including High School Musical costar Zac. The two have been close for years, though Ashley's BFF and Zac's ex, Vanessa Hudgens, wasn't spotted partaking in the party. Ashley did get a piggyback ride from muscle-bound Zac, who showed off his shirtless physique. Zac Efron also supported Ashley Tisdale at the premiere of her latest DVD release earlier in the Spring, and they both had downtime to enjoy the long holiday weekend and the big two-six for Ashley.