It all began when a group of financially pressed 14-year-olds were forced to relinquish their contraband -- M&Ms, Raisinettes and Nestle's Crunch bars.

Since they hadn't purchased their candy at the concession stand, the management of the Carrollton movie theater informed them, either they or their goodies would have to go.

The next day, the teen-agers complained to their state delegate, Thomas J. Mooney of Takoma Park. And that's how Mooney came to stand before the House Economic Matters Committee yesterday to deliver his "eating-in-the-movies" bill.

"It's not one of the profound matters in the legislature this year," he admitted, "but it has its place."

Consider the financial facts, Mooney said. A kid goes to the movie on Friday night, it's $4.50. He takes a date, make that $9. He and his sweetie decide to eat a Nestle's Crunch bar (the 2 1/2-oz. size), add another $1.50. And so on.

Sure, the moviegoers could try to sneak in candy and other snacks they bought for less money elsewhere. But, reasoned Mooney, "Why does somebody have to act like a surreptitious sex criminal in order to take something into a theater?"

Mooney's bill was vigorously opposed by the National Association of Theater Owners. If not for proceeds from the concession stand, said the association's Ira Cooke, a ticket price would have to be increased another $1 to $2. If not for restrictions on bags and bottles, he said, the rowdier element might sneak in alcohol. And if not for the special line of merchandise sold in the concession stands, the noise levels in theaters might become prohibitive.

"Most people don't realize," Cooke said, "that food sold in movies is specially designed to be soundproof. You won't find cellophane and you won't find potato chips."