Stood up for myself today

So my husband has been leaving his and his ex wife's kids with me when they misbehave. Today we were all going to go out as a family. Because of another issue in the house regarding my step kids behaviors to me i chose to stay home away from them and my husband. He heard his kids being disrespectful to me and chose to stay quite until i said something to him. He told me if i was not going to come he was going to leave lets call her child 4 with me. I said no i am not your damn babysitter take your child with your. He tried to say she is just going to be in her room i said no and if your going to do that then you need to leave 3 and 4 here as well because they were just as misbehaved. See my husband's ex wife has been calling me a baby sitter to their kids and all i am here for is to watch their kids and feed them thats my job. So my husband wont tell his bitch of an ex wife to stay in her lane and watch her mouth instead he does not defend me to her and lets her speak like that about me all the time and because of it their kids treat me like shit. So today i told him im not your babysitter. And i ment it. So he and his kids went out together while me and my 2 stayed home. Btw his kids treat my son like shit to and i stop that quick in a hurry.