Teen heartthrob Zac Efron has a secret army of fans - middle-aged women go weak at the knees when they meet him.

The High School Musical star says teenage girls are usually too embarrassed to approach him in public.

But moms use their daughters as an excuse to get his attention.

Efron says, "It's not the kids - it's not the 'gaggle of girls', it's the 'gaggle of parents'. The parents are the ones who want the pictures. The girls are too shy so it's really sweet. I love to wave at them and stuff. It's really funny."

"The parents are the most excited. The kids are like: 'Mom, let's go,' and she's like: 'No, we're taking a picture, it's really exciting for everyone in your class.' Really, truthfully, I love the kids. It's a pleasure."