Sarah Sands: What Walliams needs is a real, grown-up woman

Self-revelation is dangerous, but David Walliams (pictured) won over his critics with his sorrowful vulnerability on last week's Desert Island Discs. Those who had thought him cruel, lecherous and misogynist forgave him for his broken heart, his filial duty and his yearning for domestic happiness above hollow fame.

The beautiful women he befriended were not attracted to him, he said. The parties were a mere distraction from the inky torment of his thoughts. Matrons across middle England sighed happily as they stirred the gravy. It could not be long before Walliams was struggling with child car seats and visiting his mother-in-law.

The following evening, Walliams, 37, was at a King's Road nightclub with his spectacularly pretty 18-year-old girlfriend. I know it is fashionable to say that a man who has many gorgeous girlfriends is evidently gay, but I tend to take these things at face value.

What is more unsettling is the age discrepancy. There is a natural order to things that demands you put away 18-year-old girls and silly coloured cocktails after your twenties. I happened to be at that Issa after-show party on Monday night and blinked with self-mortification. Raffles feels like a venue for teenage parties.

The trouble with refusing to surrender youth is that one minute you are a dude about town and the next a parody of the late Sir Dai Llewellyn. Age differences need not be an obstacle, but the younger has to submit to the tastes and bedtimes of the elder. If lopsided relationships could be isolated to Caribbean beaches they might survive, but the couple have to return to the battle-ready glances of the ex-spouse's friends and a minefield of embarrassment.

There may be many compensations for having a very young lover but it is not worth the sacrifice of an equal and adult relationship. While the cameras caught the knotted, exhausted grief on the faces of David and Samantha Cameron last week, they paid less attention to his light hand on her shoulder, a gesture of absolute solidarity and love. Madonna has a trophy in her new young lover but probably not a soul mate.

Walliams's young girlfriend may well be more interested in going to parties than listening to his moody musical memoirs. On the whole, the young just want to have fun.

What I cannot weigh up is how much Walliams really believes in the poignant folly of fame. Hugh Grant is a different act and 10 years older, but has a similarly keen, mocking intelligence and has also played the self-loathing card. All is vanity except for the loving goodness of their mothers. Grant becomes likeable again when he talks of the teasing banter he shared with his mother as she was dying. Walliams's personal joy lies not in premieres and parties but in proving his worth to his mother by swimming the Channel.

I am no psychologist, but is the Ancient Mariner's journey across seas and nightclubs rooted in an inability to find a match for the maternal ideal? Or is this just my bourgeois hope as I prepare the Sunday roast? Was David Walliams confessing on Desert Island Discs or laughing at us?

Sarah Sands is Editor in chief of British Reader's Digest