How good is The Kiss?

The Potterites lining up for opening showings of "Harry Potter and the Half-Blood Prince" have studiously examined the film for its treatment of these crucial plot points:

• The development of Tom Riddle from creepy orphan to wicked Lord Voldemort.

• The revelation of the dark magic of Horcruxes.

• The question of whether Hermione performed a Confundus charm during a Quidditch match.

These things are very important in the Potterverse.

But for some readers, they are not as important as The Kiss.

This is the brief lip-lock between protagonist Harry and his pal Ginny, though the sixth installment of the teen wizard series contains a cornucopia of other bumbling hormonal activity.

Ginny snogs Dean. Ron snogs Lavender (ew). Hermione snogs Cormac (eww). Ron and Hermione fess up to their festering crush (fans anticipating that kiss, alas, must wait for Movie 7 or 8).

"Half-Blood Prince" is when Cupid's arrows fired in nineteen-freaking-ninety-seven finally hit their targets.

This is major stuff. The Potter series is first and foremost an adventure series, but it's also the place where many young readers first read about stomach-butterflies, heartbreak and the agony of unrequited crushes. Harry/Ginny, Romeo/Juliet, Luke/Laura — or at least, they did until a sultry young half-vampire couple appeared on the scene.

"Am really looking forward to not only *THE KISS*, but the scenes before it when Harry is having his internal struggle," wrote a fan who calls herself dumblegirl on a Harry Potter message board. "This is one of the best parts of the entire series ... his future, his heart, his life. Oh, warm fuzzy feeling!"

Dumblegirl posted this back in 2007. That's when everyone thought "Half-Blood Prince" would be released in 2008. But Warner Bros. postponed the November release for money reasons, and then Summit Entertainment swooped into the slot with a paranormal romance of its own — a little movie called "Twilight." And the whole kiss thing changed context and meaning. "Twilight," a vampire romance based on the first book of Stephenie Meyer's series, tapped into the youth market that J.K. Rowling had been grooming for more than a decade. "Twilight" also has A Kiss. It is 29 seconds long. It happens in a dimly lit bedroom, in underwear, between human Bella, who is eager for hanky-panky, and her vampire boyfriend, Edward, who resists because he's still not sure whether he wants more to smooch Bella or drink her blood.

For an analysis of these two approaches in teen romance, let's go to John Granger, author of "Harry Potter's Bookshelf" who is working on a book about "Twilight."

"Harry is basically a Gothic heroine," Granger says. He "may have a love figure, but you get the (romantic) payoff after a long wait." Meaning ... " 'Harry Potter' is 'Pride and Prejudice' with wands."

It's all misunderstandings and mistaken identities and people feeling awkward. And when relationships do happen, they are subtle, hand-holding affairs.

With "Twilight," it's all glistening chests and luscious lips and naughty thoughts. Swooning is prevalent.

" 'Twilight' is written from the perspective of a girl," says Lori Joffs, founder of fansite Twilight Lexicon.com. "I think we can kind of agree that boys are clueless." If Hermione was the narrator of the Harry Potter series, Joffs says, "she might secretly be thinking bodice-ripper thoughts about Ron."

But one wonders: Does all of "Twilight's" undead intensity usurp the "He's Gross/I Like Him/This Is Awkward" innocence of "Harry Potter"? Interested parties have been speculating: One article suggested that Warner Bros. had ripped off "Twilight's" marketing, with moody love-triangle posters reminiscent of the ones for "New Moon," the second book in the vampire saga.

Has "Twilight" increased heart-thumping expectations of paranormal teen romance?

"I don't know where the market is going in terms of teenage sexuality," says Tim Shary, author of "Youth Culture in Global Cinema." From the mid-1980s through the mid-1990s, he says, "Teenagers in movies hardly had sex at all" — and never without the safe-sex talk. Now, "emphasis has shifted more to the emotional consequences" of physical relationships.

"Harry Potter" hints at emotional dilemmas: whether Harry and Ginny's jokey friendship can withstand the added pressure of kissing. "Twilight" brings cinema-goers back to the chaste '90s: Beware, Bella, sex might kill you.

These questions vex and perplex as we enter the theater for an early screening of "Harry Potter and the Half-Blood Prince."

The Kiss? It's short and sweet, fully clothed, friendly, basically an elevated peck, no wandering hands, no saliva.

It's pretty good.