Advice

So my husband works for his step dad and I guess sense he's his step son gives him the right to yell at him everyday?

So his mom just texted me (my mother in law) and says this...

Now I have nothing wrong with her but I feel like I should award her and her husband with time with my son when her husband constantly screams at my husband everyday at work- advice guys? What should I say? I know I dont have to let her see him but I would love advice on what I should say or do.