I knew nothing about the play, but I knew one of the cast and for a while I wondered whether they'd improvised it. In fact the writer is Nigel Williams, who wrote Elizabeth I for Helen Mirren, and this world premiere performance was part of the National Theatre's Connections Festival of Youth Theatre. I left the theatre smiling, which is always a good start.

As the programme says: "Mark is in love with Susie, Lou is in love with Sam, but Sam (although he doesn't know it) is in love with Emma and, to make things even worse, Lou may be in love with Susie's brother Pete!" And that's just weird! says Susie.

So, it's a farce, and characters hide and meet each other in more-or-less plausible combinations. But they're almost always all on stage together, relying on freezes and lighting shifts to focus on the action of the moment. And several of these freezes involve two, three or four of the players in some fairly convincing fights. I didn't expect blood and guts, but they looked as if they meant it enough.

So, it's eight teenagers on their own on the internet when they sit on their own boxes. Then they go to a party in the real world, where Susie wants to pair Lou off with Sam and really wants to meet Dave, who is actually Mark but he didn't have the confidence to show his own photo on the web so he used that of a relative. Are you keeping up?

There's some fairly crude Jewish-Israeli-Muslim stuff, but why should young mouths observe the niceties? And it all comes out well in the end, with what some of a former generation might have called a miscegenation. Oh, and two characters at different times wear a gorilla suit.

These were assured performances from a tight group of young players. Much of the audience would have been friends and family, gritting their teeth against the Bad Words we were all warned would come out of those young mouths, but the applause was genuine rather than relieved or desperate. An evening well spent.