Dane DeHaan and Cara Delevingne
Luc Besson’s new blockbuster Valerian and the City of a Thousand Planets is excellent - that is until Cara Delevingne and Dane DeHaan appear on screen.

Valerian opens spectacularly with a 400-year montage sequence showing humans coming into contact with increasingly amazing alien life, before we are introduced to a planet where the blue inhabitants are at one with nature. But then things turn dire as we cut to the worst leading protagonists of the year, lazing on a fake beach.

The relationship between Delevingne and DeHaan is supposedly a will they/won’t they romance in the operatic space tradition of Princess Leia and Han Solo, but it doesn’t take long before you’re hoping that they never see each other again.

In the absence of any tension or connection between the pair, the only evidence that they are romantically entwined is provided by the poor dialogue they have to whisper constantly at each other, which amounts to Valerian professing his undying love and desire to marry Lauraline, and her answering she wouldn’t trust him because he’s a cad.

AO Scott in The New York Times describes their relationships thus: “They are also at least potentially a couple, a fact which authorises a lot of dialogue that might technically be called ‘banter’ but that seems to have lost its snap after passing through Google translate a few times too many. Anyway, Valerian and Laureline are as cute as a pair of baby salamanders.”

What makes them so bad?

Dane DeHaan is the darling of the indie movie circuit and usually terrific but it takes a Bruce Willis sized-dose of charisma to sell blockbuster dialogue, as the scripts are usually just a nuisance to get out of the way to the next explosion. DeHaan just doesn’t have that kind of presence and he gives the impression that he read this script while holding his nose. His heart is just not in it.

Opposite him, Cara Delevingne seems to think that acting means to smirk and raise one of her famous eyebrows. It might work for her many magazine covers, but she’s not the great foil that we need her to be. It’s odd that she’s so fey given that Besson has created so many fabulous and strong female leads in his movies.

He got the performance of her career out of his then-wife Milla Jovovich in pop sci-fi The Fifth Element, turned the young Natalie Portman into a superstar with the remarkable Leon and had Scarlett Johansson power past the plot holes as an action heroine in Lucy.

In movies it’s standard practice to have chemistry readings between actors before they are officially allowed to sign on the dotted line. One can only assume that the chemistry test between DeHaan and Delevingne involved a periodic table.

As such they join a long list of screen couples that look like they’d rather be hanging out in Guantanamo than be in acting with their co-star.

Remember when everyone was excited about the first Star Wars prequel, The Phantom Menace until Natalie Portman and Hayden Christensen (remember him?) showed that they did not have any romantic force.

Fifty Shades of Grey was going to be the raunchy movie to match the famed S&M books but, with the director Sam Taylor-Johnson and the book’s author EL James at loggerheads, it seemed that was enough tension and drama on the set for actors Jamie Dornan and Dakota Johnson, who pout and pose their way through the picture like rabbits in headlights.

In A United Kingdom, Rosamund Pike and David Oyelowo have a love that is supposedly of Romeo and Juliet proportions, but it’s not just the people of Botswana who can see that there is something amiss with this romance, and it has nothing to do with race or nationalism.

It’s all the more fun when big movie stars who supposedly ooze sex appeal end up giving each other the dead fish treatment, so step forward Johnny Depp and Angelina Jolie in The Tourist, Meg Ryan and Russell Crowe in A Proof of Life, Marion Cotillard and Brad Pitt in World War II drama Allied as well as The Colony stars Emma Watson and Daniel Brühl.

Movie sets seem to be a place where real life couples venture to get laughed at. The artifice of making a film seems to kill their real life fire. What else can explain the eyes-glazed-over looks of Jennifer Lopez and Ben Affleck in the much-maligned Gigli.

Nicole Kidman and Tom Cruise appeared on screen three times together with mixed results. They met on the set of Days of Thunder, then went Far and Away together, but it’s their appearance in Eyes Wide Shut that always gets thrown up in these discussions.

But are they really bad in it? Or was Stanley Kubrick manipulating their lack of chemistry as part of the plot.

It’s a film that is ageing well, unlike the marriage of Kidman and Cruise which ended soon after the long London shoot.

The relationship of Angelina Jolie and Brad Pitt is bookended by two movies, the fun action flick Mr and Mrs Smith and the dreary end-of-the-affair romantic drama By the Sea.

A special place in movie hell seems to be reserved for movies with May to December romances that are not Pretty Woman. So that means a whole list of Woody Allen films that make you go eeugh rather than ooh.

The 1957 musical Funny Face saw a 58-year-old Fred Astaire waltz his way to a 28-year-old Audrey Hepburn. Partly this can be blamed on the Hollywood star system in which supposedly men get sexier as they get older, while their leading ladies stay the same age.

There is also the category of actors who didn’t get along on set but often these have ended up producing interesting match-ups in pretty great movies.

Many years down the line, Tony Curtis said that his immortal words “It was like kissing Hitler” about smooching Marilyn Monroe in Some Like it Hot was a joke, but not before it had become movie lore.

Harrison Ford and Sean Young despised each other so much on the set of Blade Runner that they apparently called their love scene “the hate scene”.

The new favourite to argue over at dinner parties is the third pairing of Emma Stone and Ryan Gosling in La La Land.

Personally, I think they got the tone right here, unlike the debacle that was Gangster Squad, so sometimes these things are just in the eye of the beholder. - The Independent