NOT SINCE Al Pacino's "Scarface" has one man put so much up his nose for his art. Until now. Sean Penn, costar of the spy story "The Falcon and the Snowman," seems determined to prove that things go better with coke. Penn, as addicted dope dealer Daulton Lee, emerges as the star of what is a disappointing, mostly two-man drama about teen- age turncoats.

Timothy Hutton grapples unsuccessfully with an equally unsympathetic part -- Christopher Boyce, a divinity school drop- out turned traitor.

The two young talents, as inept at picking parts as Nastassja Kinski, play the spawn of permissive America, rich kids brought up in the good old days of alienation and radical chic. Boyce gains access to top secrets at an aerospace plant and, in a fit of idealistic pique, engages his childhood pal Lee as a courier who sells them to the KGB in Mexico City.

It's a methodical, long-winded work based on the real-life shenanigans of two disenchanted brats from Palos Verdes, California. John Schlesinger, who also directed "Midnight Cowboy" and "The Marathon Man," tries to combine the best of both earlier films by marrying male bonding and spy thrills. But his work is uninspired here, sheepish, and loaded down with obtrusive, overworked symbolism. The director, a Brit, doesn't have a gut feel for his material, set in '70s America, a time and a place that didn't make much sense even to those who slept through it.

Schlesinger really can't say what makes a traitor tick. Boyce states a high, if misguided, purpose of reforming the CIA: He's the Democrat. Daulton does it for a stake in an intercontinental drug business of his own: He's the Republican. Treason plays no political favorites.

Scenes meant to be otherwise revelatory are aborted before they climax. One in particular finds Boyce in a ruckus over poetry with his former FBI dad (Pat Hingle). The gist is that Boyce and his father don't really understand each other. Is that all it takes to turn a would-be saint into a traitorous twit?

THE FALCON AND THE SNOWMAN (R) -- At area theaters.