Gee, it’s tough for straight women and men to lock lips and fates together on screen. One obvious problem is that virginity, marriage and children are no longer necessarily compulsory, which has complicated the happily-ever-after thing. Writer and director Leslye Headland gets this, but she apparently enjoys a challenge, so she has worked hard to complicate her romantic comedy "Sleeping With Other People," about a man and a woman who do everything to stay apart even though they and everyone else know they were, sort of, made for each other. 

At least that’s the way they were written and directed, although how they come off on screen is another matter. The reluctant lovers, Lainey (Alison Brie) and Jake (Jason Sudeikis), meet cute at a 12-step program for sex addicts, having already met equally cutesy in college a dozen years earlier when she was pulling some crazy-chick nonsense by pounding on another guy’s dorm-room door. In an unpersuasively staged flashback, Lainey and Jake cozy up, losing their virginity, before going their separate ways; now, he is a serial womanizer and she’s still in love with her college obsession, Matthew (Adam Scott, wearing a straight face and a comic-strip villain’s mustache). 

Like a lot of American independent-movie characters created on a budget, Lainey and Jake do a lot of sharing, often in medium close-up; like too many of those characters, they also yak as if they’ve spent years on the couch. Even as students, they talk about themselves with a practiced air, which is why their self-actualized chatter soon sounds canned. Their acute self-consciousness about why they do what they do nominally explains why, right after they reunite, Lainey and Jake vow to preserve their refound friendship by never sleeping together. The attractively matched Brie and Sudeikis joke through this foundational exchange, as they do throughout so much of the movie, with racing patter, some nudge-nudge, wink-wink and not a trace of believable feeling. 

Headland has a concept for a latter-day screwball comedy — two romantically challenged friends whose hang-ups create a roadblock to coupledom — but she doesn’t have the jokes or the emotionally textured characters that can fill in that conceit. Specifically, she doesn’t have fresh takes on the romantic comedy — sex, gender or why, even as the world changes, it never gets old watching people fall for each other. And it’s love that explains why the genre remains so durable. In the 1930s and ’40s screwballs that philosopher Stanley Cavell calls the comedies of remarriage, men and women trade insults and seductive looks as they work through what it means to be modern. Decades later, they are still trying to figure it all out, though now with more therapy and sex than pratfalls and wit.