Last Night's Television - Otto: Love, Lust and Las Vegas; BBC3; Desperate Romantics, BBC2

Painting by numbers

Oh look out, here come the PRB crew, striding down the street, line abreast, like some weird hybrid of a Danny Boyle movie and a costume classic. It's "Paintspotting", or rather Desperate Romantics, with Dante Gabriel Rossetti as the Renton character, all roaring assertive appetite, and Millais and Holman Hunt as his sidekicks. They're on their way to give the Royal Academy gang a good kicking and it is already clear that the opening disclaimer on Peter Bowker's drama – laying claim to the same "imaginative licence" and "inventive spirit" that characterised the artists he's writing about – was a necessary warning. "Entourage with easels" was reportedly how the executive producer referred to the BBC's series, so what you get on the soundtrack is driving, rock-inflected music and what you get on screen is cheerfully and cockily vulgar.

For some reason, Bowker has invented a fourth gang member to help us out with the story – Fred Walters, a puppyishly eager fan of the Pre-Raphaelite Brotherhood. One of his tasks is to sort out their careers for them, procuring the right kind of model (Lizzie Siddal) and fixing up for Ruskin to come to their exhibitions. His other task is to stand around looking mopey and crestfallen when they all ignore him or steal his best lines. Ruskin, incidentally, is played by the excellent Tom Hollander, here struggling with a role that is three parts dictionary of quotations to one part tortured sexual repression. He managed as well as any man could in the scene where Ruskin flies in panic from the marital bed only to find a couple bathed in red light rutting on his desk, but I doubt that any actor could have prevented the tableau from provoking a giggle.

Desperate Romantics might have been better, curiously, if there had been more of such moments rather than fewer. It was never quite recklessly anachronistic enough to suggest a defence of predetermination for those moments in the script that seemed more like a spoof of an artistic biopic than a genuine attempt to rise above its limitations. "So...," says Ruskin when he bumps into the posse at one point, "... the Pre-Raphaelite Brotherhood... the group of radical young painters who announce themselves by thrusting notes through letter-boxes in the middle of the night." People do this sort of thing quite a lot – telling people what they know already – and Dante Gabriel Rossetti even does it to himself, introducing himself to Ruskin with a tabloid strapline: "Artist, poet, half-Italian, half-mad".

Peter Bowker's script scrabbles a bit effortfully for vigour. "I've seen stains on a chamber pot with more artistic merit," roars Rossetti, after finding that his pals have been bumped out of sight at the Royal Academy by a painting of three cherubs. But it was notable that the moments the language really came alive were when Ruskin had supplied the words. At one point, Fred stops him in his tracks by quoting his advice to young painters: "They should go to nature in all singleness of heart and walk with her laboriously and trustingly having no other thought but how to penetrate her meaning, rejecting nothing, selecting nothing, scorning nothing". It's an intriguingly sexual choice of word – penetrate – given that he could never manage it with his wife, and it gave the line a little frisson that lifted it above the boilerplate jauntiness that surrounded it. Incidentally, since I suspect that Bowker is not going to get an easy ride with this drama, it's only fair to remember that he also wrote the wonderful Blackpool and the recent Iraq drama Occupation. Count this one as on off-day.

In Otto: Love, Lust and Las Vegas, Otto, a man with Down's syndrome, and his carer, Billy, went on a lads' trip to Las Vegas, in a somewhat mysterious extension of Otto's mum's attempts to get her boy laid. Was he going for sex or for a holiday? And who had paid the bills, given that Otto's pursuit of what he bluntly called a "shag" had already stirred up some dubious offers from lad mags to pay for a trip to a prostitute? Never mind. Otto had a whale of a time, and we got to have our preconceptions about mental disability and sexual appetite taken for a wild bareback ride. His mother came across as admirably feisty in her defence of her son's right to an ordinary life, but the fact that Otto needed a carer nearby while he enjoyed a lap-dance couldn't help but raise the possibility that what should have been his private life was being exploited as a public spectacle. Then again, he didn't look worse than any man would in this peerlessly undignified position, and the experience seems to have altered his feelings about commercial sex. The idea of prostitutes, he later declared roundly, was "disgusting". I hope he finds a nice girl soon and that the cameras are nowhere near when he gets his wish.