[Wayne] and his sister [Amy] threw a surprise pizza party for [Wayne]'s son, [Robert].
('Robert', 'Amy')
[Wayne] and his sister [Amy] threw a surprise pizza party for [Wayne]'s son, [Robert].
[{('Robert', 'aunt', 'Amy'): [('Robert', 'father', 'Wayne'), ('Wayne', 'sister', 'Amy')]}]
['father', 'sister']