Over four decades, David Mamet's Sexual Perversity in Chicago has, via two dramatic mutations, evolved (or should we say "devolved"?) from a busy, profane study of modern mating rituals to the blandest of industry-standard romcoms. We're all for reinventing the source text. But when your intention was always to use the cookie cutter, why bother nodding the head towards any largely imagined inspiration?

The character names have been retained from Ed Zwick's 1986 brad-pack romp About Last Night . . . , but the location has moved from Chicago to Los Angeles and the language has been further softened.

Largely an African-American affair, the film studies the intertwined relationships of two very different couples. Bernie (Kevin Hart) and Joan (Regina Hall) are noisy, unpredictable and outspoken. Danny (Michael Ealy) and Debbie (Joy Bryant) are civilised, aspirational and less interesting than watery porridge.

While the first couple bicker, bellows and hump, the second work through the usual crises in the usual order. He can’t quite commit. She remains suspicious of an earlier girlfriend. He eventually grows up. Then a minor dispute splits them up and, as the credits loom, viewers who have never seen a film before wonder foolishly whether the rift can ever be healed.

Ealy and Bryant are good looking. They can deliver their lines without swallowing their tongues. But so unutterably bland are their personalities that it proves hard to focus one’s eyes when either is on screen. Meanwhile, Hall and the ubiquitous Hart work hard at delivering some amusing curlicues at the film’s edge.

To be fair, they do a pretty decent job: the apparent improvisations are more diverting than the scripted platitudes. But the impression remains of a gutless entertainment that retains only a few tiny, largely insignificant traces of its distinguished origins. What’s the point?