“Under Her Control” is a surrogacy-gone-wrong thriller wrapped in a “Devil Wears Prada” package.

This Spanish melodrama starts slowly and lumbers towards a Big Finish that isn’t nearly big enough to atone for the tedium that precedes it.

First-time feature director Fran Torres gets a few hot sex scenes into his debut, and spills some blood in the finale. But the middle acts are one long siesta thanks to a low-stakes script (by Laura Sarmiento Pallarés) dependent upon not a whole lot happening.

Cumelen Sanz plays Sofia, an ambitious sales clerk at a Madrid bargain fashion store with dreams of interning and then working for the great Beatriz Gaya (Aitana Sánchez-Gijón) a self-made Madrileña fashion tycoon.

Sofia is a devout, superstitious Catholic from Colombia not shy about dropping in on her Colombian beau, Nacho (Alex Pestrana) at the various rental properties he shows to prospective renters.

It’s not just siestas that Spaniards take over the noon hour.

Sofia’s fervent prayer comes true and she lands the internship as Beatriz’s assistant. But just as she’s learning the ropes and starting to get her ideas “out there,” all that unprotected sex comes home to roost.

She can’t tell Nacho. The priest she consults just shames and threatens her that “There is no worse crime than spilling the blood of the innocent!”

Meanwhile, single, 50ish Beatriz has figured out that her careerism and years of “swipe right” level relationships have run out her biological clock.

“By the time you know what you want, you’ve no time left,” she sighs (in Spanish, or dubbed into English) to her OB-GYN (Vanessa Rasero).

All it takes is her picking up on Sofia’s “condition” and the young woman’s desire to get out of it for Beatriz to spring into action, and enlist her gyno-pal and her lawyer (Pedro Casablanc) in the scheme.

They will manipulate and bribe Sofia, tricking her out of an abortion, plotting to separate her from Nacho during the pregnancy, keeping everything secret so that the baby can be passed off as belonging to Beatriz.

For all their machinations, they should take heed when Sofia brazenly asks for double their offer and a contract guaranteeing future employment. She’s not some naive waif, fresh off the boat from South America.

But she finds herself “Under HER Control” when Beatriz parks her in a country estate with no phone, where CCTV cameras will watch her every move and her health regimen will be strictly monitored.

And then the pregnancy progresses, hormones kick in and the real games begin.

The plot has dopey, obvious contrivances designed to make all of this plausible, which they don’t.

The performances are on low simmer as the characters turn towards sinister or allegedly desperate, and do nothing to engage us in the proceedings.

And the payoff is flat, with even the violence failing to up the heartrate as it supposedly ups the ante.

Rating: TV-MA, violence, sex, nudity

Cast: Aitana Sánchez-Gijón, Cumelen Sanz, Vanesa Rasero, Pedro Casablanc and Alex Pestrana.

Credits: Directed by Fran Torres, scripted by Laura Sarmiento Pallarés. A Netflix release.

Running time: 1:50