It’s a rare novel that can serve as the basis for two really bad screen adaptations, but Scott Spencer’s “Endless Love” has now achieved that select status. The twin misfires, however, are very different creatures. Franco Zeffirelli’s 1981 version of the story was so extravagantly overripe that it invited howls of derision. By contrast Shana Feste’s remake is so glossy and bland that you’d swear it had migrated from the CW onto the big screen, and find yourself inclined to doze off as it unspools.

Originally Spencer’s David was a deeply troubled teen, obsessively longing for the even younger Jade and engaging in self-destructive behavior in stalking her, though the novel obscures that by making him the narrator, who naturally presents things from his own skewered perspective. Zeffirelli played down, but certainly did not entirely eradicate, the boy’s dark side in favor of presenting the tale as a doomed “Romeo and Juliet”-style romance. Director Feste and her co-writer Joshua Safran go far further in that direction. As played by Alex Pettyfer, David is about as dangerous as any teddy bear not voiced by Seth MacFarlane. Sure, he still has one criminal incident in his past, but he’s totally cleaned up his act; his relationship with his hard-working mechanic dad (Robert Patrick) is excellent, and his infatuation with graduating classmate Jade (Gabriella Wilde) is totally chaste, based not merely on her beauty but sympathy for her plight.

That’s because the real obsessive in the narrative is Jade’s father Hugh (Bruce Greenwood), a heart surgeon so grief-stricken over the death of his eldest son that he’s placed all the hopes he’d focused on the dead boy onto his daughter instead, simply dismissing his undisciplined younger son Keith (Rhys Wakefield) as a hopeless case. The result is that she’s had virtually no social life in her high school years, concentrating instead on studies that will secure her a place in the med school from which Hugh himself graduated. David, touched by her lonely plight, shows her a bit of kindness, and she responds enthusiastically to his modest advances. Soon their relationship has bloomed into young love, much to Hugh’s distress. He does everything he can do to thwart a romance that threatens all his plans for his child, even after David has accidentally learned that he’s cheating on his wife Anne (Joely Richardson). But needless to say the course of true love cannot be denied.

Feste treats this mawkish folderol with ludicrous sincerity, even tossing in a brief balcony scene designed to remind you of Shakespeare, a cruel comparison indeed. In Pettyfer and Wilde the film has a perfectly lovely pair of young lovers—he’s even more attractive when bemoaning his losses late in the picture (photogenic stubble on his face) than he was clean-cut toward the beginning, and she’s engaging even during moments when Jade does some very silly things. As a whole the picture looks as pretty as they do, with Andrew Dunn’s camerawork emphasizing the lustrous character of the California backgrounds. Even the L.A. airport is made to appear positively palatial.

The simple-mindedness of the approach, however, often makes the movie feel like a succession of airbrushed magazine ads featuring ever-so-beautiful young people. And it has a terrible effect on the supporting cast. Patrick comes off best, subduing the usual hint of menace to give a pleasantly laid-back turn. By contrast the talented Greenwood gives one of his worst performances, exhibiting near desperation in trying to invest shallow, boneheaded Hugh with a measure of nuance. Richardson is similarly stymied by Anne, who finds a spine only at the last minute (of course). Special opprobrium is due Dayo Okeniyi, who’s incredibly irritating as David’s fast-talking best friend, and Emma Rigby, whose stilted turn as the girl with eyes for David is almost as annoying.

The sad thing about all this is that Spencer’s book might have served as the basis for a really interesting film. But neither Zeffirelli’s flamboyant soap opera nor Feste’s even more defanged version does it justice. Her adaptation is, however, at least true to Spencer’s title in feeling interminable.