Netflix really only has itself to compete with in the newly-revived teen romantic comedy genre. Theatrical studios gave up on making such films and getting them right a generation ago.

But young fans of Netflix’s bubbly (“The Perfect Date”) or bawdy (anything with Joey King) entries in the field will learn a hard lesson with the sequel to the very best film the streaming service has made for teen romantics.

It’s damn near impossible to catch lightning in a bottle twice.

The adorable and bubbly “To All the Boys I Loved Before” earns a sauntering, meandering and much less fun second chapter with “To All the Boys: P.S. I Still Love You.” Not only does the title kind of give the whole game away, but it dawdles so much and throws up such contrived obstacles to love that it darkens some of the glow of the original comedy in the process.

Lana Condor still makes a lead so cute you want to pinch her cheeks. Go-to “teen” hunk Noah Centineo (“The Perfect Date,” TV’s “The Fosters”) still has that offhand, jockish charm.

The soundtrack still sparkles with hits ranging from “Then He Kissed Me” to tunes to CYR, Lola Marsh, Anna of the North and Bora York and covers of “Girls Just Want to Have Fun” and “I Want it That Way.”

We pick up the story (there’s a refresher video of the first film) with virginal Lara Jean (Condor) trying to get a grip on her giddiness and wrestle with “this relationship thing.” She’s got her first real boyfriend and he takes her on their first real date — dinner at a fancy eatery, a magic lantern launch afterwards.

Perfect, right?

“I just don’t want us to break each other’s hearts!”

Trouble comes from that first date, from those “other” love letters than lonely Lara Jean sent to all the boys she crushed on throughout her young life in the original “To All the Boys,” from beau Peter’s “reputation” and Lara Jean’s inexperience at all this stuff.

As in, he’s smooth, but he takes her places he’s taken other women. He reads her a poem for Valentine’s Day and she thinks he wrote it just for her. And she gets a reply from a letter to a middle school crush (Jordan Fisher), which “complicates” things like, you know, her feelings.

Lara Jean’s still living too much in her head (endless scripted interior monologues), and uncertain as to how to navigate these complicated feelings. Holland Taylor plays Stormy, the retired flight attendant at the nursing home where Lara Jean volunteers, the older woman who gives this motherless teen romantic advice.

But that nursing home is also where John Ambrose (Fisher), that middle school crush, is volunteering. Sparks fly! Or, um, should. He’s musical, thoughtful, a lot of things Peter is not.

Some scenes color in around the edges of the movie even if they don’t advance the plot — dissecting octopi in biology class, a Korean New Year celebration with Lara Jean’s mother’s family. There’s a middle school time capsule, tree-house confessions, and a possible new romance (Sarayu Blue) for widowed Dad (John Corbett).

But really, this movie plays like the middle picture in a trilogy — a romance in a holding pattern. The arguments are realistic but inserted as mere plot requirements. The spark between the leads fizzles, new sparks don’t replace those and the slight edge the first film had — his mean girl ex (Emilija Baranac), her obnoxious meddling little sister (Anna Cathcart) have lost their sting.

Which isn’t surprising, because in rom-coms, you only get to surprise us once. God help them if Netflix is indeed planning a third film in this story, because they’ve wrung most of the delight out of it.

MPAA Rating: TV-14, teen partying, discussions of sex

Cast: Lana Condor, Noah Centineo, Jordan Fisher, Anna Cathcart, Madeleine Arthur, Emilija Baranac, John Corbett and Holland Taylor

Credits: Directed by Michael Fimognari, script by Sofia Alvarez and J. Mills Goodloe, based on the Jenny Han novel. A Neflix release.

Running time: 1:42