Always thinking my ex is "ridiculous"

Hi Coaches, I’m noticing that a lot of the time when getting into discussions with my ex about the kids or things that we still share, if we disagree on something, I’m thinking the thoughts:
– “why dont you just take some responsibility”, or
– “thats fucking ridiculous”, or
– “that is so emotive and manipulative”.

These discussions are usually always over the phone, often result in back and forth bickering and are sometimes within ear shot of our kids. I’m not showing up how I want to.

Each time I have this result, I run a model on them to try to understand why I am so immediately drawn into this and create an argument. In this situation, there is not yet any space between him saying the thing and my thought, feeling, reaction. A couple of my models are as follows:

C: Ex-Husband says “No, I won’t ask your dad for the sheets, he needs to give them to me”
T: Why cant you just take some responsibility
F: Frustrated
A: Reactive. Fire up, growl noise (“ughhhh!”), defensive tone, rasied voice, argumentative sentences from me
R: Argument/Bickering

C: (above)
T: Thats fucking ridiculous
F: Exasperated
A: Reactive. Roll my eyes, sigh, Fire up, defensive tone, rasied voice, dismissive and argumentative sentences from me
R: Argument/Bickering

What I have learned from my models so far is:
– It is my unchecked reaction to what he says that starts the argument
– Each time its one of three thoughts and feelings
– Its fast: There is little to no space AT ALL between him saying the thing and my thought/feeling/reaction
– Its usually on the phone, but can happen in person too
– Usually after I have requested something of him

I know I can create an intentional model, but what I really want is to be able to understand WHY I’m so over the top reactive here. Why in this situation there is not yet any space between what he says and how I react.

My question is:
1. Can you please check my models? and
2. Do you have any questions I can ask myself, or suggestions on models I could run to help me gain more insight?