Spiders, flavored slime and acting secrets

NEW YORK -- Some preteen stars, the kind you want to avoid, are divas in training. Some are picture-perfect.

Make that almost perfect. Emma Watson, 12, and Rupert Grint, 14, who play the title character’s friends in “Harry Potter and the Chamber of Secrets,” made no missteps as they chatted up the second Potter movie, which opens Friday. During a recent visit to Manhattan, they were pleasant in the extreme.

As he talked, Rupert, who plays Ron Weasley, filled pages of hotel paper with black spiders. Then he began sketching a jowly, whiskered man with a bloated stomach. Who’s that, Rupert? Mr. Potato Head?

Emma shrieked with laughter. “It’s Rupert’s father!”

And so it was -- the father who was sitting quietly at the other end of the table, not chaperoning so much as posing for his son’s unflattering caricature.

Rupert offered no clue as to why he was turning his father into Mr. Potato Head. The spiders, however, were easy.

In “Chamber of Secrets,” the wimpish but loyal Ron gets the fright of his life from a horde of spiders, one of them a monster with an 18-foot leg span.

That wasn’t acting. “I was actually scared,” Rupert says.

On the other hand, vomiting slugs was great fun.

“That was my favorite scene. I had to try out all these different flavored slime. Chocolate, pep- permint, orange. They tasted really good.”

Emma chuckled. Her character, the brilliant Hermione, suffered no such indignities. But she does spend much of the movie petrified -- as in motionless. “That was a wax model of me. In the gap where I was petrified, I went back to school.”

If Rupert’s drawings indicated a hidden aspect of his personality, Emma’s were all sweetness and light -- names of her classmates in balloon-like letters punctuated with hearts. Then she started a second page -- girls with hair. How does she get her own shoulder-length auburn waves to look so good?

“OK. It’s basically just wet it, curl it and bouff it up. My hair’s big, but it’s not big-big-big.”

Her clothes were fab -- a fuzzy, gray cowlneck, a DKNY denim skirt with a ruffle, brown suede boots. Is that how she dresses at home?

“I wear a uniform at school, but I have these massive bell-bottom flares, and my mom really disapproves of them.”

Rupert, his voice deeper than in last year’s “Harry Potter and the Sorcerer’s Stone,” kept it simple: black T-shirt, jeans, Converse sneakers. Have Rupert’s parents been good about his fame?

“Yeah, they’ve helped me keep my feet on the ground.”

Is he rich?

“Kind of.”

How about Emma?

“I don’t really know how much money I have because my parents take care of it.”

Rupert, who is the oldest of five, is back in school now -- he’s the British equivalent of a high-school sophomore. The teachers play up to him, he says, “which is quite a good thing. It gets me out of some homework.”

Emma is into athletics. “I’m very, very sporty -- I ski, I fish, I do field hockey and tons of stuff.”

How about academics? “Well, I’m doing art at school.”

Is she smart like Hermione? “No! I’m the complete opposite!”

In “Chamber,” Hermione continues to mix potions and cast spells with precocious dexterity, but there’s a human side to her. She hugs Harry -- “embarrassing” -- and she has a crying scene. Was that tough?

“No ... you try not to blink for as long as possible. Then you think of the saddest thing possible.”

But the sadness ends there. “I think I could be 100 years old and in my rocker, but I’ll still be very proud to say I was in the ‘Harry Potter’ films,” Emma says.

Rupert: “Yeah, me too.”