Up front, I’d just like to apologize to the third “Fifty Shades of Grey” movie and everyone involved.

Back in the halcyon days of February, I deemed “Fifty Shades Freed” the worst movie of 2018. I’m sorry. I was wrong. I’ve now seen something far worse and something far, far less funny: the R-rated, foul-mouthed puppet movie “The Happytime Murders.”

This is the rare comedy without a single funny moment. Not a glimmer of wit, not a moment of invention, not a character you can stand to listen to for more than two consecutive seconds. It’s shrill. It’s unpleasant to be around. It’s the cinematic equivalent of the high-frequency noise emitters that keep teens from loitering in front of convenience stores.

“The Happytime Murders” is what we talk about when we talk about movie hell.

To be clear ... a violent, vile and dumb movie starring puppets can work, and has worked. You might recall “Team America: World Police.” There’s also 2016’s computer-animated “Sausage Party,” which similarly (and successfully) raunched up a medium typically reserved for family entertainment.

Making an intended comedy so completely bereft of laughs is a noteworthy accomplishment. (Any movie that earns an “F” grade has accomplished something.) But what makes the utter failure of “Happytime Murders” all the more impressive is the number of talented people who were involved:

» Brian Henson (director), as in son of the late Jim Henson. The younger Henson directed two classic “Muppet” movies: “Muppet Christmas Carol” and “Muppet Treasure Island.” He also produced the movie under Henson Alternative, a division of The Jim Henson Company.

» Todd Berger (writer), who wrote and directed the very funny 2012 apocalypse movie “It’s a Disaster.”

» Melissa McCarthy, Maya Rudolph, Joel McHale and Elizabeth Banks — all in this terrible movie for some reason, pulling what moves they can to make bad scenes and bad lines work, but only adding to the overwhelmingly depressing nature of the whole rotten endeavor.

Film Review - The Happytime Murders

Joel McHale is an FBI agent in “The Happytime Murders,” which takes places in a society where puppets are second-class citizens.

Not that it matters, but here’s the plot: Puppets coexist with humans in modern society, but as second-class citizens. There’s some queasy attempts at social commentary here: puppet segregation, puppet racial slurs (they call them “socks”), puppets bleaching their felt to appear more human.

Phil Phillips (voiced by Bill Barretta) is a private-eye puppet and disgraced ex-cop. Through his hard-boiled detective monologues, we learn that he was kicked off the force for his inability to shoot another puppet.

Phillips spends his days shaking down puppet porn shops and beating up puppet-parts poachers, until his dark puppet past catches up with him. The puppet cast of an ’80s TV series is being picked off one by one, and Phillips is the prime suspect.

To clear his name and crack the case, Phillips teams up with his old partner, Connie (McCarthy). They get some help from Phillips’ ex-lover (Banks) and his loyal secretary (Rudolph). An FBI agent (McHale) is hot on their trail.

Onto this rickety frame of a premise, “Happytime Murders” slathers an endless parade of bad jokes — 95 percent of which are related to puppet genitals and/or puppet bodily fluid.

Orson Welles once famously never said, “The positive effect of a gag involving puppet genitalia is inversely proportional to the number of puppet genitalia gags in your film.”

But we get dozens of them. They never stop. Cow puppets and octopus puppets shooting scenes in puppet pornos. A puppet-y homage to the most famous scene in “Basic Instinct.” (My hat’s off to the lucky craftsman who got to make that!) And an interminably long puppet sex scene that climaxes in silly string.

This movie’s manner of humor spurred a grade-school memory. Back in sixth grade or thereabouts, I had this friend who would intentionally not flush toilets in the school restroom. He would then hang out in the restroom long enough for someone to walk into the stall and gasp in horror. And he would laugh and laugh and laugh.

I think he’d probably love this movie.