Last Night's TV - Lip Service, BBC3; Tom Daley: the Diver and His Dad, BBC1

I don't know if you've seen much pornography recently, and certainly I haven't, but as far as I can remember the one distinguishing feature common to all productions in the genre, fornication aside, is an unfailing lack of interesting conversation. There is chitchat, all right, but rather than being dialogue in the conventional sense, or even remotely interesting, such talk as occurs is a prelude or postscript to the main event. It is, in other words, a facilitator and a distraction.

I got the same sense when trying to engage with the pathetically vacuous plot of BBC3's latest attempt at captivating the youth of today. That this hour of spirit-cripplingly tedious drama should be topped and tailed with two sex scenes, in which vigorously nubile young women pleasure each other, gives you some indication of its banality.

Set in Glasgow, this opening episode introduced us to a cast of twentysomething women reconciling themselves to the difficulties of modern life. Each one appeared to us as a giant hormonal vessel. They do the usual jobs of anxious twentysomething women: architectural practices, photography, auditioning for shopping channels. But what exactly the purpose of their existence was, other than to fret about the insignificant, was hard to fathom.

So we were left wondering on what grounds we should care about them, or feel any sympathy with their travails. Being of a post-university age, they have none of the childish charm of the characters in, say, Skins; nor does the background scenery and title music do all the work the actors can't, as happens in Dawson's Creek. That leaves as the only interesting thing about them – oh... did you guess yet? – they're lesbians.

Lesbians! Lezzers! You know, girl-on-girl. Yes – kerching! – that is the point of this show. To prove that dear old Auntie Beeb can broadcast a bit of 21st-century smut and get away with it. Now, I'm not altogether au fait with the lesbian sensibility, but if I was, I should think this the most patronising drivel that could ever be broadcast about a subject close to my heart.

You know it's patronising because every five minutes there is an utterly fatuous remark dressed up as profundity. "I'm not cut out for this whole blind date thing – you don't know what to expect," one sister said early on. You don't say! Later, jobbing actress Tess Roberts, grappling with the trauma of singledom, said: "I do what most lesbians do: stare at women hungrily, and pray that someone else makes the first move." Me too, sister. At the end of the show, Frankie, played by the improbably beautiful Ruta Gedmintas (she looks like a Topshop mannequin), was causing another sister to have an orgasm, in the cellar of a funeral parlour. They're surrounded by rotting cadavers, so Frankie looked over at one and suggested he'd died and gone to heaven. Died... in a funeral parlour... geddit?

I feel some sympathy for, and solidarity with, the cast, who are clearly talented and produce more than passable performances. But they seem to me part of an absurd experiment, gone horribly wrong. In trying to make a point about the importance of engaging with lesbian issues, this show ends up trivialising them. The lesbians are presented to us not as interesting people, or characters who warrant sympathy; rather, they matter purely because of their sexual preferences. That is immature, patronising, and unrealistic. It also guarantees a lack of interesting conversation. Which leaves as the only merit of last night's episode brief glimpses of pornography, and as for how they rated I couldn't possibly comment.

On a happier note, and still talking about young, talented people, you felt that Tom Daley was improbably capable long before, at the back end of the hour, the diving prodigy revealed his eight A*s at GCSE. Some kids have all the luck. Others don't, and work incredibly hard at being successful. Daley showed exceptional dedication to his cause, is perfectly charming, and endured family trauma with unconventional fortitude. For capturing this completeness of character, Tom Daley: the Diver and His Dad deserves top marks.

I don't think I've ever seen a father's love for his son presented more charmingly on the small screen. Daley, you'll recall, is the now-16-year- old diver who went to the Beijing Olympics as a Great British hope, having at one point been British champion for three successive years, and a European champion too. With marvellous archive footage from when he was 11 years old, he was shown as the font of all his family's hopes, coping with the extraordinary pressure so often bestowed on child prodigies.

But what started as a show about Daley – slowly morphed into a show about his father, who has a growing brain tumour. What could not be made explicit, but was very obvious, was the contrast between father and son. The former's unrefined West Country accent rubbed up against young Tom's slightly effete manner. Fat, balding, tumour-ridden Dad wore lifeless surfing T-shirts; muscular, naked Tom was blossoming into manhood. If it seemed unfair, that's because it was, and though the curious and unsatisfactorily abrupt conclusion was frustrating, we were left with the feeling that there are people out there really striving to achieve, rather than having dilemmas over which shoe to put on first, and asking us to care on the grounds that they generally prefer copping off with girls than boys.