Theatre Sweetheart Royal Court, London

Nick Grosso's Sweetheart unfolds in a cultural scene where to be almost 30 is to be guilty, virtually, of a crime against life. Wrinklies may take heart, though, from the fact that it shows how being young, cute and sexy can constitute a liability, causing the sufferer to drift from futon to futon and bed to bed in an indefinite postponement of finding any real purpose. It also reminds you that, in the relationship stakes, a healthy bank balance can be a potent recompense for middle-aged baldness.

Grosso's very entertaining first play, Peaches, offered a series of acutely observed snap-shots of lads forced to pretend to more success with women than they were evidently achieving. In Sweetheart, the young twentysomething males are on the other side of the sexual Rubicon; it's the trickier business of love that's now the bugbear.

Flitting around north London (the various postal districts are flashed up on a sharply focusing all-white set), Roxana Silbert's excellent production follows the fortunes of Charlie, whose sole occupations seem to be charming, seducing and irritating girls and coming up with fine sounding pseudo- philosophical reasons for being, to all intents and purposes, a layabout. "'You are still doing nothing if you do something," he opines, a perception we all have from time to time, without wanting to build a life on it.

The play pulls off the attractive feat of extending to Charlie a sympathy that's rigorously untainted by indulgence or special pleading. As played by the superb Joe Duttine, there's a trace of genuine existential insecurity underlying the character's practised, sparingly humorous sexual appeal. There's also a much less practised melancholy because of his recently failed love affair with Toni, a young nurse. A scene in which he almost inveigles her to taking him back ends with an image that demonstrates this cool play's finely balanced passion. Thinking he's got things sewn up, Charlie heads into a self-entranced mime-along to the song "I'll be there for you". Before she leaves, unnoticed, Kate Beckinsale's Toni watches her performing ex-lover with an intent sadness, her eyes starting to spill with tears. She's sorry for him as well as for herself and that emotion is contagious.

Grosso's chopped, highly formalised dialogue captures the defensive, testing-the-waters feel of conversation between not particularly articulate young adults. He also has a way with symbols that make their point without being too overt. In Charlie's grip, the kite flown on a weekend break in Wales crashes to the ground because he won't learn the knack of "compensation". He suggests that refusing to replace a broken watch is a conservative feminine trait; but his own watch is revealingly unreliable.

Most of the girls he meets work in television. But real life, he argues, involves watching television, not making it - the latter activity effectively ruling out the former. Nicola Walker's likeably shrewd Kelly gives the best lie to Charlie's posturings by confessing that she does not find her production manager's job fulfilling (that's merely what you're meant to say, she contends). Therefore, honesty and being in work are not necessarily mutually exclusive.

In Peaches, Grosso wrote a play that was itself a small but perfectly formed peach. This new one is another.

n To 24 Feb (0171-730 2554)

PAUL TAYLOR