A man has appeared in court charged with murdering his wife and her lover on New Year's Day.
Rhys Hancock, 39, of Etwall, Derbyshire, allegedly stabbed Helen Hancock, 39, and Martin Griffiths, 48, at the former marital home in Duffield.
Hancock appeared at Southern Derbyshire Magistrates' Court, speaking only to confirm his name, age and nationality.
Magistrates were told that Hancock, a head teacher, and his wife, a PE teacher, had split up some time ago and Mr Griffiths was her new partner.
Police had been called to the home just after 4am on Wednesday and found Mr Griffiths already dead and Mrs Hancock severely injured.
Paramedics tried for 15 minutes to save her but she died.
Police arrested Hancock outside the house, where prosecutor Jeanette Stevenson described him as "compliant".
The Hancocks' children, ages nine, four and three, had been staying with a grandparent when their mother died.
Rhys Hancock will remain in custody until he appears at Derby Crown Court on Monday.
Derbyshire Police have appealed for witnesses to come forward if they had spoken to either of the Hancocks or Mr Griffiths in the days leading up to New Year's Eve.
Detective Inspector Steve Shaw said: "As with any investigation, it is vital that a full picture of the incident is able to be established."
The school where Mrs Hancock worked said she had been a "well-liked member of staff who made a real difference".
Mr Griffiths's colleagues at creative design agency 22 Create said he had "inspired many with his enthusiasm, positivity and ideas".
Derbyshire Police has referred itself to the Independent Office for Police Conduct regarding contact between the force and Mrs Hancock before the incident.