Theatre is full of families. Actors have a tendency to beget actors, and producers like nothing better than casting real-life relatives on the grounds that it supposedly makes a play's relationships "more real".
Timothy and Sam West played father and son in Henry IV, and assorted Redgraves and Cusacks have turned Three Sisters into family affairs, but this show leaves the competition standing.
Martinez's extraordinary theatrical cross between stand-up comedy, a game show and a live photograph album features Martinez plus two very special guests: her Spanish mother and utterly English father - and all three play themselves. The most important fact about the whole thing is that her parents are not actors. Imagine suggesting that your parents join you, on stage, to talk about your relationship with them. Now imagine the result. It is truly hilarious.
Martinez promises, as we are greeted with the cheesy tune from This is Your Life, that she will expose the naked truth about family relationships. For one ghastly moment you think you're in for an American-style piece of confessional theatre, but part of the genius of the show is Martinez's ability to put everyone at their ease.
From the subtly faked nervousness of the opening, through to the "live satellite link-up" with her party-giving sister, everything balances on a delicious knife-edge between beautifully thought-through ideas and spontaneity. Half of the fun is watching the exchanges between "the performer" and her parents and trying to work out what's scripted and what's not.
Martinez, of course, recognises this and plays upon it to sublime effect. The show both celebrates and mocks the notion of being "on the knife-edge of contemporary queer theatre" - a term guaranteed to send many people rushing for the exits. It not only works like a dream, although it is undoubtedly experimental, but it goes down a treat because it is quite absurdly funny.
At one point, her scientist father tells us that he'd much prefer "a nice script" with "real acting". Just when you think your head is going to explode with the games of the reality we're watching - is this scripted, improvised or what? - he performs the "Seven Ages of Man" speech from As You Like It. The moment is charged up with layer upon layer of game- playing, but you almost don't notice because it is so touching.
Everything in Mark Whitelaw's superbly paced and exquisitely directed evening is played as truthful, sophisticated comedy, but the most remarkable thing about A Family Outing is its ability to ask profound questions about theatre and families without you even noticing. Tiny time bombs keep exploding in your head, but you're too busy laughing to notice.
To 31 Oct, then 17 to 21 November (0171-637 8270)