Neil LaBute’s fascination with shifting sexual politics in the world and the workplace is the crux of “Dirty Weekend,” a rather dull and talkative comedy about two mismatched colleagues trapped in Albuquerque for a day of true confessions and misbehavior.

It’s not even the weekend. This happens on a Monday. But it’s dirty enough, I suppose.

Les Moore (Matthew Broderick) is the stiff senior salesman set to make the company’s pitch to folks in Dallas. Naturally, it’s some sort of make-or-break sale. There’s a lot riding on it.

Natalie Hamilton (Alice Eve) is a younger Brit who figures she has just as much status, and that maybe she’s come along to see to it that sweater-vested Les doesn’t screw this up.

But the weather parks them in New Mexico. On a Monday. And Les can’t stand staying in the airport. There’s something drawing him to town, something very out-of-character that happened to him there, once. And Natalie is curious. She won’t let him trek in alone.

It’s not like they’re married, he protests. “We’re more like bandits, desperadoes.”

Exactly, she says. Like “Butch & Sundance.” And Butch never let Sundance ride off alone.

“Together…the whole POINT of the ampersand!”

LaBute tries to hide the nature of their relationship, but we can see, from the start, that they aren’t a couple. Broderick has a middle age spread, and Eve? Still “Out of My (and his and yours) League.”

The pair have drinks, get personal and exchange secrets. His has to do with what happened to him in Albuquerque. Hers has to do with that leather collar that her turtleneck sweater hides. A “dirty weekend” is when you take a no-holds-barred cheater’s break from a committed relationship. He’s married, she’s living with someone. Who will crack?

LaBute, in his 50s now, gives Natalie nasty, blunt vulgarisms that she trots out as she drags information out of Les.

“You know what? Women never used to talk like that.”

It never amounts to much. The performances feel mannered and stage-bound thanks to dialogue built on overly structured exchanges. The banter is more frank than funny, the situations a tad too primly handled to pay off. LaBute’s early films, based on his own plays (“In the Company”) could be read as a reaction to his Mormon upbringing. “Dirty Weekend” sees him age out of that edginess, thinking his dirty thoughts and sort of losing his nerve with what to do with them.

MPAA Rating: unrated, with frank sexual discussion, profanity

Cast: Matthew Broderick, Alice Eve, Phil Burke
Credits: Written and directed by Neil LaBute. A Phase 4/eOne release.

Running time: 1:33