Ashley Tisdale and Lucas Grabeel have reunited and gone back to their High School Musical roots.

The co-stars, who played siblings Sharpay and Ryan Evans, performed a duet of their song “What I’ve Been Looking For” and even spilled some behind-the-scenes stuff too.

Apparently the pair didn’t get a long at first with Ashley explaining: “We hated each other! I’m not kidding! I think we just didn’t know each other and I was a lot like Sharpay and Lucas was like ‘Who is this person?’”

Ashley and Lucas are firm friends now though and have performed an updated cover version of their HSM hit.

Check it out here:

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