M.K.
Full moon!!! But seriously, I totally get what you're saying! My daughter is the worst at this!! She'll come home from school in a bad mood and start yelling at me for no reason. I just tell her I'll talk to her when she cools off. I usually go in my room and play games on the computer! Then later I'll go talk to her; on one occasion, she told me a girl at school took her lunch and then lied about it. My son gets in a bad mood also, but he just clams up or gets a little moody with me but never yells at me.
I think it's because they know we'll keep loving them no matter what and they feel they can do/say anything to us. Taking a break from each other for a few minutes usually works for us. Then I also tell my kids I don't appreciate being yelled at; they apologize and we move on. It's all good!!
Hang in there!!