In pop culture, we often take for granted the Adonis (so many visible abs dull the senses) and overlook the waistline of a funny or straight man. Strangely, the everydude build of Jason Segel is a frequent topic of fascination. He made it that way when he dangled his half-fluffed cock in front of the country in 2008's Forgetting Sarah Marshall, his male lumps taking a backseat to the taboo.

Last year, he told David Letterman he was forced to lose 30 pounds after his 6-foot-4 frame hit 245. He virtually repeated that conversation with Letterman this week regarding his new movie, The Five-Year Engagement. "I was told that it had to be conceivable that [co-star] Emily Blunt would ever choose me to be her husband. Which is fair," he said of the studio's mandate.

That body of his is as much of a curse as it is a gift – it's practically a selling point for Engagement. In another round of promotion, he told the panel of the Today show that, "apparently me being naked is funny: onscreen, in my personal life. If I take my clothes off it's met with hysterical laughter, for some reason." And a funnyman will do anything for a laugh, right?

The weirdest (and only interesting) thing about The Five-Year Engagement, then, is how covered-up this notoriously nude guy is. You see his ass twice — once peeking out of an apron with the body of Michelangelo's David silk-screened on the front in what appears to be a Sarah Marshall reference. One scene requires him to travel some distance on foot naked, and yet he's only shot from the chest up. That's true also of a scene in which he hops out of bed after his character Tom fakes an orgasm with his fiancée (Blunt's Violet). All the sex scenes (and there are roughly half a dozen) take place under covers, which feels almost pointedly fearful of Segel's body. I have no sense of the state of Segel's paunch, and believe me, this is something that I look for. For someone who talks about being nude so much, he barely is. He told Today that a full-frontal scene in Engagement was cut because "they couldn't find a lens wide enough." Uh, OK.

There is a sense of shame in this strategic avoidance and masking, but I can't figure out the source. Is the studio embarrassed of the doughy schlub who's a talented writer and capable box-office draw, or is Segel less comfortable with his bod than he lets on? If it's the latter case, there is some kind of synergy with his emasculated character, who's forced to leave a great chef job in California when his fiancé lands the researching job of her dreams in Michigan. "You have no idea what it's like to be the guy in a relationship and not have a job I'm proud of," he moans. He gets into wedding planning, partly because of his demoted status in the relationship and partly because it means getting to test taste a bunch of delicious food. And then he becomes obsessed with hunting, thus letting his dick swing back around.

If the prospect of a five-year engagement sounds insufferable, this film lives up to expectation. There are some strange, funny lines ("You were shooting telepathic wiener missiles at her face") in this film about two utterly unremarkable people doing unremarkable things for over two hours, and that's it. The nuances of Tom and Violet's relationship are surface level (that's not figurative — she refers to intimacy as getting "weird"). One joke about the word "peonies" sounding like "penis" was already scooped earlier this year by The Celebrity Apprentice, of all things.

If I were Sandy Kenyon coming at you from the back of your taxi, I would have opened this review with, "The Five-Year Engagement isn't as long as the time period of its title, it just feels like it." The movie is a total waste of time and Van Morrison fetishism (so much on the soundtrack). It isn't intricate enough to profile a relationship with the depth of an Annie Hall, nor is it bawdy enough to satisfy on a gross-out level.

"Sometimes the biggest balls are the ones left unused," says Segel's character on not wanting to reproduce at one point. He offers absolutely no proof. The Five-Year Engagement is nude and not-nude but mostly just neutered.