Lyttelton theatre, LondonCoughlan plays a barmaid, alongside Derry Girls co-star Siobhán McSweeney, in JM Synge's 1907 classic Every woman loves a bad boy, or so the cliche goes. Here it is tested when Christy Mahon walks into a pub to confess he has killed his father with a farming tool. It's not quite the truth but he is, to his own surprise, turned into a local celebrity. Women flock to see him and men hail him…