Just try to set an example, ignore what you can. If they are really obnoxious, it's up to your spouse to deal with them.
No.
Outlaws are wanted...... inlaws aren't.
petheriká
Ask your spouse
Inlaws.
No.
but your brother is her husbande
Sounds like a wonderful Wedding Present for the new inlaws. The Phantom of the Opera in Toronto will be perfect and enjoyable.
Yes, because he is married to Dorothea Hurley
Grandfather. Or his name, the same as you would any other inlaws.
Manners is a noun.
school manners