No one teaches you how to have a relationship. So people just kind of default into patterns that are often toxic.
It’s why taking a step back and being deliberate about how to communicate is so important. There needs to be a shared understanding and deliberateness about how to intentionally communicate.
And it needs to be something that applies equally to everyone involved. No copouts, no special circumstances that only go one way, there need to be firm, hard rules with specific consequences that apply evenly to all involved that are arrived at communally, and not unilaterally.
It takes two to tango.
The defensive lashing out type stuff happens because he hasn’t established firm boundaries around it. And she’s probably lashing out about stuff because… Well. Doesn’t matter, really.
There need to be firm boundaries about how to have a discussion that apply evenly to both of them. Both of them need to buy into these rules. When the lines are crossed the discussion ends.
This isn’t about shutting down a discussion but having the awareness to recognize constructive versus destructive discussions.
Setting reasonable, adult boundaries and rules, sticking to them, and establishing that certain behaviours are problematic are the only way this gets better.
If she’s unable to recognize her own defensiven ss as a problem and work on it all of this falls apart but having the framework in place will allow transparency into the why of it.
No problem.
I’ll add one other thing: Others have mentioned couples therapy. This is a great idea. Even if the relationship is already over, worst case scenario is they both gain some insight into their own toxic behavioural patterns to make their next relationship better.