Tony and Greg appear to have the ideal set-up: commitment to one another but with the option of an “occasional bit on the side”. But how firm a foundation is this for a relationship? What if one of them falls for someone else for longer than a night?

Set just 15 years after the decriminalisation of homosexuality (this production marks the 50th anniversary of the legislative landmark), Kevin Elyot’s 1982 play raises pertinent points about the challenges gay men faced negotiating the world of relationships that finally dared speak their name: about faithfulness and whether love can survive without it; about how to be simultaneously honest with another and true to oneself; about the desire for intimacy but the fear of achieving it.

There is much to enjoy in the production. Director Adam Spreadbury-Maher’s decision to have Lee Knight’s Tony and Elliot Hadley’s best pal William pootling about the set as the audience take their seats is a masterstroke, establishing from the off the recognisable dynamic of a gay male friendship forged on clubbing, cruising, and laughing over the night’s exploits the following morning.

The opening scene in particular is full of (sometimes improbably) killer lines; whether anyone has ever breezily described a trick’s flat as “an emetic combination of Salvador Dali and the Ideal Home Exhibition” is debatable, but who wouldn’t want to?

Knight gives a tender, believable performance as the self-doubting Tony. Despite a touch of the Frank Spencers, Tom Lambert commits wholly to the role of naïve young seducer Robert. But it is Hadley – all Kenny Everett muck and Bet Lynch brass – who outrageously steals the show, while hinting at the loneliness and longing beneath his assiduously maintained armour of camp. When not on stage, his absence is felt. The production also suffers from distracting design decisions (Mozart on the stereo and the Queen Mum on the wall – really?!) and the perennial problem of how to stage a convincing sex scene.

But niggles aside, “Coming Clean” is an entertaining show that – ending not with the anticipated bang but an ambiguous whimper – leaves you with plenty to ponder.