story: [Preston] who is [Edward]'s father grounded [Edward] after finding out what [Edward] had done at school. [Mack] and his wife [Stacy] will be at the play. [Preston] 'son [Mack] could not believe that his father bought him a coffee machine for his birthday.
query: ('Preston', 'Stacy')
clean_story: [Preston] 'son [Mack] could not believe that his father bought him a coffee machine for his birthday. [Mack] and his wife [Stacy] will be at the play.
proof_state: [{('Preston', 'daughter-in-law', 'Stacy'): [('Preston', 'son', 'Mack'), ('Mack', 'wife', 'Stacy')]}]