The son-in-law erected a monument to his grandfather.

Is your sister's husband a door-to-door son-in-law? In fact, it is legally obligated to support the elderly on both sides. As for whether to erect a monument to his old man's house, this matter is not among the maintenance. It is a form of caring for the elderly, and it is good for the elderly when they are alive. As for what will happen after his death, that is another matter. If the economic conditions are good, you can do it completely. One is to care for the elderly, and the other is to educate children to learn to honor the elderly from an early age. And this thing is not a door-to-door son-in-law, I can't do it.

As for how you get along, as a normal relationship, you should not have any opinions or prejudices, or care more about him. As a member of the family, is your relationship still not good?