In the world of music industry accounting, the term 'fruit and flowers' is famously a euphemism for drugs. Hurts are one of the few touring bands where that entry on the ledger means exactly what it says. The duo's florist budget easily outstrips The Smiths and might even give Elton John a run for his money.

Hurts clear out a hectare of Holland, nightly. From the opening number to the encore, there isn't a song during which singer Theo Hutchcraft doesn't throw handfuls of carnations into the crowd. The fact that he comes bearing flowers makes total sense. Theo Hutchcraft, at least the Theo Hutchcraft as presented to us via Hurts' 2010 debut album Happiness, is total Boyfriend Material: a devastatingly handsome man who who will "turn temptation down" and "never let you down", looks great in a suit, has cheekbones you could chop out a line with, and remembers to bring you flowers. This is why many women of my acquaintance, and more than a few men, go a little bit funny at the mention of his name.

The swooning recipients of his floral gifts on this occasion, an intimate showcase for Hurts' upcoming third album, are 600 of their rabidly devoted German fans. The Manchester band are bigger in this region of the continent – Germany, Austria, Switzerland – than they are at home, and if it comes as any surprise that a band with Hurts' line in elegant and elegiac synthpop chime with the tastes of Mitteleuropa, then you haven't been paying attention. The fact that Hutchcraft has had the courtesy to learn a bit of German (Hurts have even covered Rammstein's 'Ohne Dich') doesn't do any harm, either.

The Lido is a beautifully battered old dancehall in the northern part of Kreuzberg, and – perfectly, for music as cinematic as that of Hurts - was formerly a cinema where, legend has it, Bowie and Iggy used to watch old movies during the making of Heroes and Lust For Life. Kreuzberg, you will doubtless be aware, is – along with neighbouring Friedrichshain, just across the Spree – Berlin's hippest district. But it is nowhere near as aggravating as that makes it sound. 'XB' is one of a handful of places on earth (along with San Francisco, Barcelona and, if you'll pardon the smugness, my own adopted town of Brighton) where I've walked the streets and sensed that I'm breathing the air of real freedom, not McFreedom. It's genuinely a place where it feels like 'we' have won.

The difference between Kreuzberg-Friedrichshain and, say, Hoxton-Shoreditch is that gentrification has largely been averted, or at least slowed (even though people will tell you it was better ten years ago; the hallmark of any great neighbourhood). This is largely due to Berlin's enlightened policy of strict rent controls, but also because the scene developed in an entirely different way. Instead of rich kids slumming it in an 'edgy' locale while vaguely pretending to be artists, the dilapidated Kreuzberg was repopulated by a very mixed influx of anarcho-punks, Turkish and Vietnamese immigrants and the elderly, attracted by the cheapness when it was surrounded on three sides by the Wall and living under the shadow of the wrecking ball. So, unlike its London counterparts, where entire areas have been passive-aggressively ethnically cleansed using the silent weapon of money, Kreuzberg remains an area of genuine integration rather than uneasy coexistence, and retains its radical heritage: Reclaim The Streets murals adorn its buildings, and 'Refugees Welcome' banners hang above fast food outlets.

It wasn't always so utopian. The biggest local employer for much of the 20th century was the Osram light bulb factory. The company's own product, with cruel irony, enabled longer working hours and night shifts in the factory, thereby contributing to the erosion of workers' rights. Under the Nazis, it was repurposed as a munitions works, and its German employees were augmented by forced labourers – slaves, essentially - from the Soviet Union. As a show of loyalty to the Führer, as well as a display of the efficacy of its bulbs, the owners erected a spectacularly-lit shrine to Hitler on the factory wall.

Tonight, the Osrams – yes, I really am doing this - are being put to a more peaceful use. Every time one of synthman Adam Anderson's melodies reaches a crescendo, Kreuzbergers are freeze-framed in the glare of Hurts' headlamps like startled rabbits, with a Hutchcraft-hurled bouquet floodlit in mid-parabola. (It's a Hurts theme: they have an old song called 'Illuminated', and a new song called 'Lights'.) Everything about Hurts is, in the best possible sense, choreographed to perfection: the way Hutchcraft's Brylcreemed widow's peak falls into photogenic tresses every time he shakes some action, the crisp white shirt unbuttoned to the sternum, the boy-band air grabs, and the way Anderson's songs build to moments of heartbursting drama, all calculated to elicit maximum screamage.

It all began with a somewhat more ragged enterprise. After Hutchcraft and Anderson's first band Bureau broke up, they formed Daggers, whose single 'Money' is one of THE great lost tunes of the Noughties (seriously, seek it out). When I booked Daggers for my London club night Stay Beautiful, Hutchcraft gave an Iggy-esque, bare-chested performance which seemed at odds with the music. Backstage, we chatted about Simon Reynolds' early 80s bible Rip It Up And Start Again. Maybe the seeds of Hurts were already in his mind.

When Daggers broke up, the core duo had a rethink. Hurts would be a neo-synthpop band for grown-ups, all about exquisite tailoring musically and sartorially. A heterosexual Pet Shop Boys or, as I oh-so-cleverly dubbed them at the time, the Het Shop Boys. It worked beautifully, selling by the truckload to a classier version of the Take That crowd. Happiness, from which no fewer than seven of tonight's setlist are lifted, had no shame about reminding you directly of the uncool bits of the 80s (little bits of melody here and there recall 'Big In Japan' by Alphaville, or 'Another Day In Paradise' by Phil Collins). The lyrics weren't always the best – there's a "down on my knees, begging you please" lurking among them – but I contend that "Time waits for no-one / So do you wanna waste some time?", from 'Illuminated', is a great opening to a pop song, turning St Marher's much-mutated proverb ("the tide abides for, tarrieth for no man, stays no man, tide nor time tarrieth no man") into a quickfire come-on.

They're big on pathetic fallacy: farewells in Hurts songs never take place under Simpsons skies, or on a mildly overcast day, and always in the pouring rain. The clouds gathered more ominously still on Exile, the proverbial and inevitable 'darker' second album: "golden days are so far away, there's a black rain up above" being a typical line. Exile included tracks like 'The Road', a 'Melody Nelson' with a grimmer outcome: the inner monologue of a hit-and-run driver who is haunted by the memory of his dying victim, whispered to the melody of Fleetwood Mac's 'Rhiannon'. And like 'Guilt', apparently a suicide note in musical form ("when you wake up happy you will thank the lord that I'm gone"). Where Hurts' breakthrough hit 'Wonderful Life' invoked the spirit of Frank Capra's classic Christmas movie as it told a tale of a woman who saves the life of a stranger about to jump off a bridge (the Severn, which inevitably calls to mind Richey Edwards), by the second album, strangers meant danger. Glass-half-full to glass-half-empty.

Tellingly, only two tracks from Exile make it onto the setlist. And, on the evidence of selections from their upcoming third album Surrender, 'Rolling Stone' being the standout example, they're turning back towards pop. The single 'Some Kind Of Heaven', with its bangin' beats, sudden drops and ecstatic yeahs, suggests the duo taken something away from 'Under Control', their chart-topping collaboration with Calvin Harris. And oh, those gargantuan, swelling melodies, as overwhelming as standing under the vaulted ceiling of the Sagrada Familia and staring up. Those moments speak louder than words, in English, German or any language. No wonder Hutchcraft and Anderson are one of British pop's most successful foreign exports. At their best, Hurts are magnificent, magniloquent, grandiloquent, grand.