You didn't have to talk to her. You chose to talk to her.
A temporary custody arrangement (which should have been done and filed the first Monday after Retro) would eliminate all these unnecessary talks and texts.
Since that didn't happen there are other ways to NOT talk to your W even when it involves your son. You could hire an e-mail intermediary service that acts as a go between when 2 spouses are divorcing.
It doesn't matter if she is refusing to come in the house because she should not be at the house anyways.
Joking around on a thread is fine but at this point somebody needs to tell you flat out to stop. If you want to attempt to have a decent co-parenting R with your W until your son turns 18 then quit the drama. The *only* thing you *have* to do is be there for your son. And being there for you son does not include you talking to your W for ANY reason. You have options, use them.
You son might be little but he is observing. He is observing how both you and your W act. I sure as hell wouldn't want a child thinking the way your W acts is normal, acceptable or tolerable. The same goes for you.
You are really only hurting yourself here. Please be honest though - most of what you say you "have" to do, you don't. You just want to. And that is okay too... do what you want. But don't say you HAVE to.