[Michael]'s sister [Mary] asked him to play cards with her, He did n't want to, he wanted to go ride bikes with his brother [Dennis] instead.
('Dennis', 'Mary')
[Michael]'s sister [Mary] asked him to play cards with her, He did n't want to, he wanted to go ride bikes with his brother [Dennis] instead.
[{('Dennis', 'sister', 'Mary'): [('Dennis', 'brother', 'Michael'), ('Michael', 'sister', 'Mary')]}]
['brother', 'sister']