The same thing has happened at our house
Now if we start raising our voices, Lily will lower her head and act so scared. I immediately stop whatever I am doing and pick her up. She doesn't seem to mind the arguing so much if I am holding her!!! I shouldn't act like that is funny, really it's not. They are just like kids and we shouldn't fight in front of them. But we are human and we will disagree. They don't seem to mind disagreeing with each other in front of US!!!