As The Overnight opens, Alex (Adam Scott) and Emily (Taylor Schilling) are failing to orgasm through sex. They opt for mutual masturbation until – oops – their young son bursts through the door to tell them that the room smells funny. The family have lately relocated from Seattle to Los Angeles, where Emily is an unspecified business suit and Alex is a stay-at-home dad.

They seem reasonably pleased, if awkward, when hatted hipster dad Kurt (Jason Schwartzman) approaches them in a playground with an offer of a “play-date”, so that his “discerning” young son might bond with theirs. Mom and dad are welcome to tag along.

Writer-director Patrick Brice mines these early scenes for maximum dinner-party-related squirm.

Arriving at Kurt’s palatial abode, Alex rips off the label from his tatty wine and claims it’s organic.

And then things get weird: one minute Kurt is discussing the water filter system he has been working on for two years, the next, he’s showing his wife Charlotte (Judith Godrèche) in an instructional breastfeeding video and his many paintings of anuses.

Alex eventually gets with the free-spirited programme and learns to love his ‘middle-school dick’: Emily is rather more freaked out.

We're accustomed to mumblecore movies meandering along without any particular place to go. But there are limits. Unhappily, The Overnight tests them.

Alex and Emily maybe comparatively square placed beside the pot-smoking wannabe wife-swappers Kurt and Charlotte, but ultimately there's not enough cultural difference between the couples to produce even the trite class frictions of Carnage.

An impressive quartet of actors do their best with limited material.

Unfortunately, their largely improvised dialogue is not enough to sustain even the meagre 79-minute running time.