Jonathan Romney on Before Midnight: The love story is over. Let the rows begin …

The old boy-meets-girl routine, it never grows stale – not at the box office. It's known in movie parlance as "meeting cute", and there was rarely a classier cinematic "meet cute" than Richard Linklater's 1995 film Before Sunrise: American boy Jesse (Ethan Hawke) and French girl Céline (Julie Delpy) meet on a train, spend the day in Vienna, fall in love, then part at the day's end. They met again, in Paris, in 2004's Before Sunset, which ended with Jesse missing his plane home, leaving us convinced that true love would prevail over the dictates of international timetables.

And here are the couple again, still together in Before Midnight, only this time the mood is more sober. Directed again by Linklater, who has co-written it with Hawke and Delpy, Before Midnight is a stiff draught of reality, showing what remains of a cute meet after all the romcom popcorn has been swept up. Since we last met them, Jesse and Céline have been living in Paris, and have had twin daughters, while his son Hank (Seamus Davey-Fitzpatrick) lives in the US with Jesse's ex-wife. And Jesse has written two successful novels based on his encounters with Céline – This Time and That Time – although she's not entirely happy about being his muse. Right now, the couple and their girls are staying in the Peloponnese, at the home of expat novelist Patrick (veteran British cinematographer Walter Lassally). It's an idyllic setting for walking, talking and literate musing.

This is unapologetically a dialogue film. The couple talk at length as they drive, then while out strolling, and finally in a hotel room, where their seemingly stable relationship begins to unravel. There's also a sequence in which they and their friends sit at lunch shooting the breeze, and you realise exactly what Before Midnight is – a philosophical symposium in the Ancient Greek manner.

I was resistant during the film's first stretch. Olive groves, children playing in the sun, well-heeled literary types at play, Christos Voudouris's glowing photography – it all seemed within an inch of Woody Allen's recent ventures, although the relaxed energy of the ensemble acting is pithier. But Before Midnight takes off in the final act when, with the couple set for a night of tenderness away from the kids, suddenly all bets are off.

At this point, Before Midnight indisputably becomes Delpy's film. Overall, Hawke's Jesse comes across as a very average, hip but gauche American litterateur – charming, playful, somewhat self-indulgent, but not half as sharp as Céline. She does a brilliantly funny routine, pretending to be a fluttering bimbo stoking Jesse's ego – but it's when they get to the hotel that the depth of her resentment emerges. She attacks him on every front, no holds barred; there's not much a woman can say to a male writer that's much crueller than, "You're no Henry Miller – on any level."

Before Midnight isn't a romance at all but an out-and-out horror story about men being from Mars and women from Venus – or more drastically still, from America and France. What's curious is that pretty much every attack Céline makes – from claiming that Jesse's writing isn't a real job to asking who picks up the socks – comes across like a parody of the tropes of feminist anger within marriage. Meanwhile, Jesse keeps trying to swallow his pride and defuse the situation with humour and charm, often inadvisedly.

Now it may be that women and men will see the film differently, and Céline's arguments come across to female viewers as well-founded. But it seems that Céline is very deliberately set up by the film as "difficult", while Jesse is presented as merely immature. Yet presumably it was Delpy herself who wrote Céline's acerbic dialogue, and Hawke who wrote Jesse as an affable, if rather insipid, nice guy. So you can only imagine that Linklater stood back to let his two leads reveal – or caricature – themselves as they wished. At any rate, the more unlikeable Céline becomes, the more Delpy emerges as a vigorously intelligent player, and Hawke as an agreeable yeoman who's just about keeping up.

A caveat, then, for anyone expecting a sweet date movie, especially if watching with the person whose hand they first held through Before Sunrise. This is a severe view of love and its sustainability or otherwise, and it's hard to know exactly where the final scene leaves the couple. But you suspect Jesse will milk the relationship for a third novel – and it'll probably be called Last Time.