What makes for a memorable show? What transforms an enjoyable night out into an unforgettable experience? It’s not always possible to assess the permanence of a performance upon exiting the venue. Sometimes, you need to get shockingly drunk, sleep on it and then make a fair assessment in the morning. That I’m struggling to recall much about last night’s gimp fight suggests that it was probably just ephemeral froth.The audience are sitting eagerly in their seats. The show is a sell out. The lights dim and on come our five protagonists. Dressed in black, with matching gimp masks, they immediately launch into a song about being ‘born that way’, complete with camp choreography. By the looks of it, a gay time is about to be had by all. Surprisingly, however, Late Night Gimp Fight turns out to be far straighter and far cleaner than one would have expected. Even when one of the cast simulates gargling with six... well, simulates gargling, it all feels quite innocuous. Indeed, there are far less knob jokes than you would expect from a quintet of self-appointed gimps.The sketches arrive fast and furious, interspersed with bursts of static from a TV set in the corner. Every time the gimps dash off stage, a familiar piece of footage flickers on screen: Bill Clinton denying having sex with ‘that woman’. On each occasion, the punchline is replaced with the words ‘Late Night Gimp Fight’. The crowd think this is hilarious. It isn’t.For the most part, however, LNGF is a big bag of fun. The sketches may be evanescent, but at the time it’s a prostate-tickling pleasure. There are some inspired moments in there, including an emotional Henry Hoover scene and a splutteringly good sketch that sees the cast dressed as toilet seats.Of the various Fringe performances I’ve witnessed this year, a quarter have had themes of incest and bestiality. Given that the remainder were children’s shows, we can up that figure to 100%. In order to provoke cheap laughs, do we have to bring Mildred the spaniel into the equation? Fair play I say. It does it for me, and I don’t see anyone in the audience complaining. For next year, however, couldn’t we have something a little more nuanced - necrophilia perhaps?