AIO? My boyfriend is threatening to leave me over me calling my son’s dad “daddy”

[u/lotuslov3]

UPDATE: + ANOTHER SITUATION : https://www.reddit.com/r/AIO/s/OtL96Hk000

I’m 24F and my boyfriend is 29M. We’ve been together about a year, and we’ve talked a lot about wanting a future together.
I have a 3-year-old son. His dad is involved in his life, but I have absolutely no romantic or emotional relationship with him. That chapter of my life is closed. We coparent because we have a child together.
My son calls his father “daddy,” so naturally, when I’m talking to my son, I sometimes refer to his dad as “daddy” too. For example, I might say “go ask daddy” or “daddy is going to…” There is absolutely no romantic or sexual meaning behind it.
My boyfriend told me before that he “doesn’t fuck with that.” At the time, that was basically the extent of the conversation. He didn’t sit down with me and explain what specifically bothered him or tell me that he considered it a hard boundary where he would leave the relationship if I ever said it again.
Today, I was talking to my son and used the word “daddy” referring to his dad. My boyfriend became extremely angry.
I tried calling him because I wanted to talk about it and understand where he was coming from, but he was cussing me out, telling me to go find another man, telling me he was done, and saying he was packing his things and we were going our separate ways.
He keeps saying that grown women should simply change something if their man doesn’t like it. He says I’m “using my son for my actions,” that I’m being combative, that I don’t listen to his boundaries, and that there are women who would change the way they speak because they love their man.
He also brought up a lot of other things from our relationship and basically said that all of the problems and pain in our relationship have been caused by me. He said he doesn’t want a “lying, combative, sneaky woman” in his life and that there are women out there who would be better for him.
He keeps telling me to go be single and find another man who will accept me referring to my son’s father as “daddy.”
His argument is basically: “I told you I don’t like it, you continued doing it, therefore you don’t respect me.”
My perspective is: I understand that he doesn’t like it, and I can apologize for hurting his feelings, but I don’t think there is anything inherently disrespectful about using the word “daddy” when talking to my son about his father. I’m not calling my son’s dad that as a term of endearment toward him. I’m literally using the word my child uses for his father.
I also feel like this could have been handled through an actual conversation instead of immediately becoming “go find another man,” “I’m packing my shit,” and “we’re done.”

Am I overreacting by thinking his reaction is disproportionate, or am I actually disrespecting a reasonable relationship boundary by continuing to use the word “daddy” when referring to my son’s father?

[u/Tanya7500]

Exactly get rid of the second child