In some Common Law jurisdictions such as the UK, Canada, and several Australian states, the defense of provocation is only available against a charge of murder and only acts to reduce the conviction to manslaughter. Until recently criminal courts have regarded sexual infidelity such as adultery and fornication as sufficiently grave provocation as to provide a warrant, indeed a ‘moral warrant’, for reducing murder to manslaughter. While the warrant has spilled over into diminished responsibility defences, wounding, grievous bodily harm and attempted murder cases, it is provocation cases that have provided the precedents enshrining a defendant’s impassioned homicidal sexual infidelity tale as excusatory. Periodically, judges and law reformers attempt to reign in provocation defences, most recently in England and Wales where provocation has been replaced by a loss of control defence that, most controversially, specifically excludes sexual infidelity as a trigger for loss of control.