Excellent actor Alex Lawther is all but insufferable in this glib, smug and overcooked high-school comedy drama, adapted from the 2007 novel by James St James and in which Trudie Styler makes her directing debut.

Lawther plays Billy Bloom, a flamboyant gay teenager who is bullied by the mean boys and mean girls at his reactionary new high school, and is obsessed by memories of his wonderfully glamorous mother, played by Bette Midler. She is now separated from Billy’s father, an uncaring wealthy man with whom Billy must now live in a vast mansion – it is difficult to tell how ironic his endless self-pity is supposed to be. But, despite being savagely beaten and actually put into a coma by homophobic jocks, Billy finds some comfort in his friendship with the school’s football star Flip Kelly (Ian Nelson), a sensitive guy who wants to be an artist. Billy finally hits on a great idea, which will fatefully divide the school: he will run for homecoming queen.

The movie is tiresome and supercilious almost all of the time, and Lawther’s performance is directed with a heavy hand. Just as Oscar Wilde said that someone was “a peacock in everything but beauty”, the movie is a comedy about gay experience in everything but humour and insight.

It has its moments, however. Billy’s self-dramatising sense of martyrdom is accompanied with a droll visual reference to the Last Supper. There is a shrewd comment on how middleweight masculinity is learned at high school: guys who are neither arty or jocks, just keep their heads down and become stolid “seven-and-a-halfs”. Plus we get an amusing, slightly bizarre cameo from John McEnroe as Billy’s grumpy gym teacher.