a close friend told how joseph o'riordan , 74 , had confided in him about the extraordinary plan for his 47-year-old wife mandy .
o'riordan , a councillor and former nightclub owner , stabbed her eight times in a jealous rage after finding out she had been having an affair with a postman .
she suffered life-threatening injuries after being knifed in the torso , chest , arms and back .