No, no, no! I don’t visit ANYONE at night without calling to see if it’s convenient, so why would it be OK to do that to my children? Husbands and wives need time alone, and 8 pm and later might just be that time. Call first, and see if they are receptive to a sudden visit. Don’t get upset if the answer is, “Now is not a good time.” If your idea is you want to see the aineklach – offer to babysit so they can go out.
PS…the child of those parents should be the one to set the boundaries with the intrusive parents. Never have it come from the in-law child. Back up your spouse and suggest an alternative visiting time.