#‘You Should Have Left’ movie review: You shouldn’t have rented this

An American man walks into a Welsh vacation house and surveys his new digs.

“For once, reality is better than the pictures online!,” he exclaims in a moment that is somehow not from a Sandals TV ad.

It’s the start of a bland movie, and the poorly written line would perhaps be true if the guy, Theo, purchased an industrial meat smoker, but this boxy, wood-paneled doomscape is no one’s idea of a cozy holiday rental.

That’s the first strike against Kevin Bacon and Amanda Seyfried’s average new horror film “You Should Have Left”: instant obviousness.

Generally speaking, there needs to be an unraveling in scary movies to give us somewhere to go. A happy cul-de-sac becomes a serial killer’s canvas, or that sweet couple in the apartment next door turn out to be the leaders of a satanic cult.

In writer-director David Koepp’s thriller, a wealthy banker (Bacon) and his B-list movie star wife (Seyfried) escape with their young daughter (Avery Tiiu Essex) to the bleakest place on Earth, where things go from dark to grim. The film begins at ugh and ends at dang. You don’t yell at the screen so much as yawn at it.

An intriguing plot then turns into a telltale heart that doesn’t pulse.

“Why do people hate Baba so much?,” the little blond girl asks her mom, Susanna, in the woods. We learn that Theo’s first wife died of an overdose in a bathtub years earlier, and the court of public opinion believes he’s guilty. It’s kinda like O.J. goes on vacay.

A notorious celeb having to explain his messy, inescapable past to a child is a smart, relevant story in the social-media age. However, while there is a psychological element to the film, with Theo subsumed by guilt that manifests in dreams, it plays as lame supernatural spooks.

The Ikea haunted house morphs shape and defies time, like it’s the Overlook Hotel’s slacker cousin, until a return to the real world becomes impossible.

From there, the film borrows from other, better stories, and then doesn’t give a return on their investment. There is a “Nightmare on Elm Street”-style twist that isn’t really a twist — more so a solid confirmation of the plainly apparent. There’s a device with a journal you’ll recognize from “Harry Potter.”

Bacon’s presence is enough to earn a passing grade, even if he doesn’t create much of a character. When we learn that he’s a banker, we’re no more surprised than had we heard he was a pro-skater or a sushi chef. In the original novella this is based on, Theo was a screenwriter.

But Bacon is Olivier next to Seyfried, who continues to pop up in movies annually although she hasn’t turned in a good performance since “Mean Girls” 16 years ago. It’s saying something that Seyfried is a modern movie star playing a modern movie star, and I still didn’t buy it for a second.

In better times for movie-going, I’d end with: You should have stayed home.