Will they grow out of i or will I get used to it?

So as my husband and I are fighting for custody of my stepsons from their maternal grandparents and guardians because their mom can no have them, I am realizing as I only have 2 younger childen if they will grow out of the misbehaving for my husband and I or if we will get used to it as they are only 6 and 8, they always seem to give us a run for our money although we love them with all our hearts I am hoping this is a phase all children go through and that they get over it or that I will get used to it because IDK how many times I have broken down in to tears. can someone give me some advise?