After spending about a month with PIL, I think I understand both of them better.
FIL is a typical Hakka man, very thrifty (he only sting in himself but generous to others) and also a male chauvinist who expects his wife to be submissive to him.
If MIL doesn't listen to him, he will shout at her and call her stupid!
MIL is a well educated lady who is a retired teacher so she is not a submissive wife as FIL would like.
Frankly speaking, I don't approve FIL's behaviour and feels sorry for MIL whenever he blows his top (don't get me wrong, he doesn't throw tantrums frequently and he certainly has never raised his voice at me. His usually target is MIL - his wife).
MIL being a very understandable wife will not confront him immediately while he is filled with anger, she will wait till he has calmed down then she will reason out to him.
She confides in me that she is not exactly pleased with FIL's but has learnt to live with him for the past 30 years.
She said when they were younger and while her mum was still alive, FIL was vey gentle to her and had never raised his voice at her.
But it changed upon her mother's demise.
She had tolerated FIL's bad temper for the sake of the family.
If not, she would have seek a divorce long ago.
I applaude MIL for her wisdom and tolerance.
I gotta learn from her to learn the trick to sustain a marriage.
I do hope that RY would never be like his dad.
I may not be able to take it if he ever throws his tantrum at me.