It’s hardly a secret, more of a golden rule, but someone here has clearly forgotten that comedy has to be funny. Instead, Elise Duran’s adaptation of a Sophie Kinsella chick-lit novel gives us a kind of unromantic noncom, a movie with no believable characters and worrying few laughs.

The heroine is supposed to relatable and real, a hapless, klutzy twentysomething chaotically muddling along, trying to figure out life. The problem is that she’s instantly recognisable from a dozen glittery, pink-jacketed books and romantic films in which female characters drink rosé straight out of the bottle.

It begins with a contrived meet-cute when junior marketing exec Emma (Alexandra Daddario) gets bumped up to first class on a flight to New York. During turbulence, believing that she is about to die, Emma spills her guts out to the ridiculously handsome guy sitting next to her (Tyler Hoechlin). In what is supposed to be an endearingly vulnerable rant, she tells him how she hates her job at an organic energy drink company, why her boyfriend isn’t the one, that she’s not sure she’s ever found her G-spot.

The next day, the hot stranger from the plane walks into her office. It turns out he is Jack Harper, the celebrity founder and CEO of her company. (You have to get past the obvious implausibility that she failed to recognise him.) Instead of firing Emma, Jack falls in love with her. But why is he always stepping away to take mysterious calls in whispers? From his waxwork-stiff facial expressions, I wondered if his secret might be that he keeps ex-girlfriends sliced up in a freezer in the garage. The actual revelation really isn’t worth the wait. Can You Keep a Secret? runs out of storyline two-thirds in, collapsing with a sigh like an overproofed soughdough.

• Can You Keep a Secret? is available on digital platforms.