Already it's hard to believe that only a few weeks ago ITV's first foray into sitcom territory for some time was regarded as a bit of a risky proposition. It was a bold decision to base a sitcom around a gay couple, particularly a pair in advanced years, considering TVs usually squeamish attitude to anybody over 40. Likewise there was a risk that a studio-based comedy, complete with a live audience, would seem old-fashioned in comparison to the darker, comedies that have dominated the schedules during the last decade.

The show turned out to be popular with critics and audiences alike, aided by the considerable star power of Ian McKellan and Derek Jacobi in the lead roles of Freddie and Stuart, not to mention the appeal of France De La Tour, playing an older, evil version of her much-loved alter ego, Miss Jones in Rising Damp.

For Jacobi, it's the quality of writer Gary Janetti's scripts that really provided the magic ingredient: "They are really special... a unique combination of reality, truth and gags, and the gags work so well because they're based in reality".

This loud and proud sitcom has dismayed many viewers and critics, although a lot of them are criticising it for being exactly what it's trying to be: catty, broad, stagey and old-fashioned. There's almost no depth behind the barbs thrown around by Ian McKellen and Derek Jacobi, who have enormous fun as a constantly warring couple. You have to just surrender and try to enjoy it as much as they evidently are.

Which camp are you in - lover or loather? If the latter, you've probably already given up on Vicious, a show that's divided viewers and critics. But if you accept and revel in the fact that Stuart and Freddie are two gay men unabashed in their extravagant mannerisms and insults, which only the unimaginative would condemn as stereotypical, then enjoy because this series gets funnier, naughtier and, importantly, kinder to its characters.

Oddly, I'm now suffering from the delusion that Ian McKellen and Derek Jacobi are in reality an item, have been for five decades, and this must be how they carry on in private.

Tonight, Ash invites his elderly chums to a nightclub in Soho. Actorly Freddie proves a big hit, but when a young woman makes a pass at Stuart, narcoleptic Penelope (Marcia Warren) comes out with four short words that almost stop the show.

'Vicious' - Series 1, episode 3

I'm actually bored of writing this review. I keep getting the image of Gary Janetti sitting at his laptop with his head in his hands. How else can I say it? The programme is a limp and listless 2/10.

Stuart and Freddie are still sneering, naive neighbour Ash is again pouring his heart out - inexplicably - to the leering pensioners, and Frances de la Tour's Violet is deciding whether to fly to Hungary to perform "depraved sex acts" (something that, admittedly, breaks with this sitcom's painful repetitiveness). But then Freddie gives an ill-informed - and very funny - masterclass on microscopically small acting parts, apropos of his Downton audition: a glimpse of how this series might have turned out had the rest of the script been nearly as clever.

The histrionics are in full flow when Freddie goes for an audition on Downton Abbey, although his only line of dialogue involves potatoes. The notion of Ian McKellen being up for such a small role is in itself funny, and the scene where Freddie sits gauche young Ash (Iwan Rheon) down for his first acting lesson is priceless.

Freddie and Stuart live up to the promise of the title tonight. They're in waspish mood, not just to each other and Ash but also to Violet - Frances de la Tour getting the best lines. "A lot of acting is just good hair," she avers, while seeking solace for a failed affair with Christoph: "He'd fly me to Hungary once a month to do... unspeakable things."

Episode review: Vicious - episode 3

After upping its game last week, Vicious took a bit of a step back this week. On the one hand, there was quite a lot of mileage in Freddie's storyline, especially as his character's only line was actually about putting some potatoes away.

Vicious makes Are You Being Served? seem almost nuanced

On the one hand, how amazing that ITV has made a prime-time sitcom about two blokes who have been in love for 48 years. On the other, would the channel have commissioned a pair of straight men to write this kind of hackneyed, stereotyped drivel?

ITV's Vicious - the sitcom even Ian McKellen can't save

When ITV's new sitcom Vicious premiered last week, I quipped on Twitter that the only way it could be any worse was if Miranda Hart suddenly popped up in it. I'd like to take that back. Because, having tuned in for the second episode on Monday this week, I've realised that this comedy can't actually get any worse.

It's amazing how quickly Freddie, Stuart and Violet, the tart trio at the sweetly sour heart of Vicious (ITV), have become as familiar as old friends.

Only two episodes in and it already feels like we've known them for years. Which of course is the case, because what this defiantly old-school sitcom amounts to is a masterclass in stereotypes.

That it scarcely matters is down to the impeccable comic timing of Ian McKellen, Derek Jacobi and Frances de la Tour, who make the absolute most of what, in lesser hands, could be thin pickings.

Last night offered mild farce in a department store involving a suspected affair and a running gag about a might-be dead dog. Every line was expertly squeezed for laughs.

The real joke, of course, is that Vicious isn't really Vicious at all - it's obvious that, not very deep down at all, they love each other to bits.