My mom has been in her feelings all day (maybe because of work or my dad). I haven't said anything…

My mom has been in her feelings all day (maybe because of work or my dad). I haven't said anything to her. Honestly I think she's mad because I won't argue with her and I won't let her go behind my back and do what she wants with my son. Desmond has actually been really good today, he's been with me, not bothering her. She's taking her anger out on him. I told my fiance about it, and he basically said its MY fault. WTF????