Jealousy and envy might be considered ‘mirror emotions’. Envy fits the facts when someone else has something one wants. It might be a relationship, a possession, status, or talent. Envy might be considered refrigerated anger, feeling blocked and an urge to attack, but with the heat taken out of it. This chapter highlights the signature features of envy and jealousy, and presents an example scenario of jealousy in which the client’s target behaviour is an urge to take an overdose after his girlfriend threatened to leave, accusing him of ‘being a control freak’. It discusses special considerations in regulating jealousy and envy. Envy often crops up in chains of bullying behaviour amongst teenagers, particularly girls. Jealousy has been a driving force for many crimes of passion, including most distressingly the murder of children to prevent an estranged spouse from having them.