The hat should’ve tipped them. The not-quite-hip/Orthodox Jewish diamond merchant hat.

That’s what Kurt is wearing when he approaches Alex (Adam Scott) and Emily (Taylor Schilling) in the park.

Or approaches their little boy, first. That’s a hint. Oh, and he’s played by Jason Schwartzman.

But he has a little boy of his own. He’s friendly. VERY friendly. He flatters them. They’re new to town, and he’s “sorta the neighborhood mayor.” He can show them around, introduce them to people.

“The Overnight” begins at that park, with Alex and Emily — whom we’ve seen coping with a tyro tyke, and struggle with their sex lives — coming to dinner with Kurt and his French wife Charlotte (Judith Godreche). Patrick Brice’s twisted four-handed comedy follows that day as it evolves into evening, and that evening as it turns into an all nighter.

Wine leads to “You guys smoke pot, right?” And that can only be chased by whiskey.

Dinner table chat leads to Kurt’s magical way of putting the kids to sleep (a planetarium nightlight, a twinkly keyboard). And that’s when things get surreal.

Brice’s culture clash comedy hurls two Seattle-ites into scenes where they’re watching Charlotte’s “acting” in breast-pump video demonstrations, or feasting their eyes on Kurt’s painting. His favorite subject? That would be a spoiler.

“This is California,” unemployed Alex shrugs. “Maybe this is the way dinner parties are.”

Emily, meanwhile, is growing more agitated by the minute. But she’s curious, too. Where is this evening going?

Brice’s script, produced by Mumbelcore Kings The Duplass Brothers, is a farce that dabbles in darkness. True confessions here, sexual mores tested there. We see where this is going long before it gets there, and in a short movie, that can be fatal.

But Schilling (“Orange is the New Black”) works up a fine, restrained outrage. Scott gives Alex his usual dopey gullibility.

And Scwartzman? He’s sort of the Mayor of Offbeat. He dials down the eyebrow-waggling weirdness to give Kurt an affably twisted personality — adoring husband, hovering/smothering dad, guy with an eye for something new. Or someone new.

Alex and Emily? They should have seen it coming.

MPAA Rating: R for strong sexuality, graphic nudity, language and drug use.

Cast: Taylor Schilling, Adam Scott, Jason Schwartzman, Judith Godreche

Credits: Written and directed by Patrick Brice. An Orchard release

Running time: 1:19