Complex #4 - D talk started / Detaching continues

[Complex]

Wow I got much better controlling my emotions while discussing things with W.
I told her I will take care of her car this time bc it's urgent, but next time she has to put her big girl pants on because I can't do stuff like this for her anymore if she wants to leave.

She reacted exactly like I predicted. She has hers on and I should put mine on blabla. Inside myself I was almost laughing how predictable it was what she said.
I was detached and very calm, although wife interpreted me being rude and almost blowing up again, but I felt far from blowing up, in good DB mode.

She also said we should split bills 50/50. I told her she should go see a mediator or an attorney then. She said she will. I guess I better go see one too asap to check my rights.

Then I said sth which I'm curious about. "I hope you don't think I'm stupid about what's going on" (I was referring to D connection to OM and that she's always getting super pretty before work etc. but I didn't say that). And she then tried to find out what my current knowledge is by asking what I think. I refused to answer, distracted from the original question. She got anxious and tried to push for an answer and I just said "does it matter what I think or know?" and refused to answer. After a few attempts she let it go. I felt like I defended myself well and with respect.

I definitely made her curious about what I know. Gets her thinking a bit.
But the mood between us is very cold. It really hurts to see how crazily distant we've become in such a short amount of time.

Any thoughts on if I did the right DB thing?