<human>: Can you provide a brief rundown of the text in within 3 sentences?

I'm at a loss. 
I know that our son can't really understand what his dad said to me but my immediate thoughts were if he's telling him this now, what is going to stop him from saying this to him in the future when he can understand better? 
I started crying and continued to get get ready for work. He went on a little longer (to me) about how useless I am. I had had enough at that point and was just telling him to shut up over and over again. When I left he didn't make any effort to apologize or even say goodbye. Now I'm in tears at work and I don't even want to go home. 

This is not an isolated incident. He often berates me in front of our child even though I have asked him not to before, and we have both agreed not to fight in front of him. This is, however, the first time he has directly spoke ill of me to our son.
<bot>: Fiance told our son I am a horrible person. Fight ensued. Don't want to go home. Don't know what to do.