Summer Kupau knows when the multiplex lights go dim, the THX logo charges up and the excitement builds with the crescendo of soundtrack, she's in for a show.

So why, just as she's wrapping herself in the surround-sound experience, does she have to put up with those goofy teenagers down in front, breaking the mood by bopping in and out of the theater?

We suspect they're movie hopping.

Local movie theater employees know some people buy tickets and attempt to see more than one movie in one session, though it is against the rules. On the Web, it's easy to find sites that advise on a strategy for this misbehavior of paying for one ticket and seeing more than one show.

But moviegoer Kupau won't do that. Besides knowing it's wrong, "I don't do it because I don't have the time," Kupau said, with a toss of her long brown hair.

Her friend, Kirsha Durante, doesn't do it, either. If she wants to see a second show, she follows her conscience.

"I did that at the dollar theater, but I went back and paid for the ticket," said Durante. "It's only a buck."

Evan Witkowski, a worker at Consolidated's Kahala multiplex, watches out for people paying for one movie and seeing others — up to five, even — but he knows it can be hard to spot. In his view, it comes down to a matter of counting on patrons to do the right thing: "You've got to trust your customers not to do it."

If Witkowski sees a movie hopper, he'll either confront the culprit or alert the manager.

"If you do catch it, you pretty much kick 'em out," he said.

At Consolidated's biggest complex, Ward employees know that movie hopping has been going on for awhile. While staffers occasionally check tickets, there isn't an usher guarding each and every auditorium for each and every screening.

The corporate folks, of course, don't condone movie hopping.

"Since we pay back to the studio, it's one ticket per viewing," said Consolidated spokeswoman Rachel Saunders, based in Los Angeles.

While he's seen no formal studies on movie hopping, or "crossover," as he calls it, Dick Westerling, senior VP of marketing at Regal Cinemas in Knoxville, Tenn., suspects the numbers aren't large, and perhaps skew to teen moviegoers who may pay for a PG or PG-rated movie and try to sneak into a R-rated one.

"Many times we have to place an usher at door for R-rated (movies), because of this," he said.

Regal has three multiplex theaters on O'ahu: the Dole Cannery 16, the Pearl Highlands Stadium 12 and the Windward Stadium 10.

Westerling said you're not just hurting the theater chain if you double-dip. "You've got auditoriums like 'Harry Potter' that are sold out, and we monitor the number of of seats sold. So if anybody was crossing over, they'd take a seat that belongs to someone else," he said.

Ticket sale counts also help the movie industry keep track of what is the most popular. And payments to some people involved in moviemaking are connected to box office take. So Steven Spielberg can get his back-end cut, which he just may use to make even more movies.

"We want to direct the ticket revenue to the appropriate studio it should go to," Westerling said. "We are very serious about not allowing individuals to cross over to other theaters they didn't purchase a ticket for."

Smaller theaters vary showtimes as a way to combat crossover. Westerling said his company staffs "with intent to monitor and eliminate crossovers from one movie to another."

At a Regal Dole Cannery matinee a few days back, moviegoer Bennett Dryden, now dad to Alyssa, age 3 months, was about to take in the afternoon screening of "Chicken Little" at Regal Dole Cannery with his daughter and wife, Stephanie.

He confessed that yes, he movie-hopped once — "when I was 16."

Dryden said he expects it happens now more than in the past, when you just had two screens to choose from. Handing Alyssa over, Stephanie said she would buy multiple tickets if she wanted to see multiple shows.

"It's probably one of the reasons we have to pay so much to see movies these days," Dryden said. "People don't have the same values they used to."

Indeed, when queried, moviegoers here said they frown upon movie hopping. One person likened it to stealing songs off the Internet. Another said it was like paying for chicken at a buffet, then piling your plate high with beef.

Westerling of Regal said a comparison to Internet piracy would be fair; both are stealing intellectual property.

Blake Umeda of Wahiawa, heading in to "Goblet of Fire" flick, said, "I never thought anybody would do that." Until a few weeks ago, that is, when he heard about someone who did it. "I thought, what a cheapo guy."

The fact remains that some people do switch theaters, sometimes because they create a justification for the act. A teacher at a private school on the island, who asked not to be named so that her mother wouldn't be identified, said her mother will elbow her family members and insist they move to another movie if she finds something offensive in their choice.

A Regal staffer laughed when she heard the story, then offered this compromise: If you don't enjoy the movie, go out and get your ticket changed.

"We're happy to switch tickets if you don't like your movie," Westerling agreed.

The basic rule, then, is to take only what you've paid for. That's what Kohler Suzuki does.

The 7-year-old was about to take in "Goblet of Fire" with his mom on the day he was interviewed.