Sean Donely , who had been having an affair with Alan 's wife , Monica Quartermaine behind Alan 's back , was the prime suspect in the murder .
Tiffany then began working for the Quartermaines following the murder of Alan Quartermaine .
Sean Donely , who had been having an affair with Alan Quartermaine 's wife , Monica Quartermaine behind Alan Quartermaine 's back , was the prime suspect in the murder .
Tiffany then began working for the Quartermaines following the murder of Alan Quartermaine .