HSM Stars Spill the Dirt
10/10/2008 AT 02:00 PM EDT
Like did you know Ashley Tisdale used to hate her HSM co-star Lucas Grabeel?
"We would hardly talk to each other," Tisdale, 23, says. "When I was auditioning for [mean girl] Sharpay, I screen-tested with him and I was acting like Sharpay. I think he was like, 'Who is this girl telling me what to do?'"
No worries, though. The two hit it off eventually and now treat each other like real-life siblings. In fact, the six stars say they have all grown into a real family onset.
Of course, Zac Efron, 20, and Vanessa Hudgens, 19, have their own special relationship. The two, who are dating in real life, said they may not be done making movies together.
"No one says it's the last time," Hudgens said. "Who knows what the future will bring?"
To read more about the HSM cast–and see exclusive behind-the-scenes pictures of the movie–pick up a copy of PEOPLE's High School Musical 3 special edition, on newsstands now.