AITA?

Long story short: my husband made me kick my mom out of our house yesterday. She made an innocent comment. I immediately knew the comment would trigger him, so I instantly defended him and called her out.

However, after she stepped outside, he blew up and told me I had to make her leave. I went outside and tearfully told her she had to go. She was crying and apologetic. I didn't have anything wrong to say to my husband, so I just did the dishes and cried in our room alone. I did not feel like sleeping in our room, so I chose to sleep in the guest room, where the newborn was. I did not make a show of it, just took my pillow in there.

At one point I did come out and ask him to, "Please turn down the TV volume," as I could hear it over the white noise even. This morning I got up and went to grab the monitor from him in our room (He keeps the monitor when i sleep with the newborn, I only recently moved back into our room). When I went to open the door, IT WAS LOCKED. Apparently, I am the bad guy here? I did what he asked me to do, then because I needed some space to avoid further escalating the situation, he got to be mad.

I literally never take space. He does. He gets angry and locks himself in rooms or even leaves. I just couldn't bring myself to talk this out last night. I was too hurt.

Edited to add: The comment was this... we were all eating and a photo of my brother-in-law and my daughter popped up on the TV. We were all saying how cute it was. I said, "I know, he loves being an uncle and a father. It's a shame my sister didn't want more kids." Then we moved on. Later in the conversation, my mom was telling me about a girl we know. She said, "Yeah, she got really lucky with her husband, he is a lot like (insert brother-in-law). He loves being a father." To which I say, "Well, what about (husband's name)? He is sitting right here, loves being a father, and has 4 freaking kids." To which she says, "Well yes, of course!" It was truly innocent.

She was just referencing a previous conversation. My mom is very kind and nonconfrontational. Also, no, he isn't controlling or alienating, but does talk extremely poorly of my family. Edited to add: I defended him because I knew the comment would trigger him, and as a wife I am loyal. Plus, I knew my mom didn't mean anything by it and wouldn't be offended by me speaking up.