I like your line "I tried living apart but it's not working for me. I need to be with my kids more, so I'm moving back into the house." I plan to practice this line and a soft delivery. I also will practice a response if she objects.
My plan is to tell her tomorrow and move back in the following day. I expect a reaction that is subtle, but very snarky.
I have remained detached all day and this has been my most productive and calm day in many weeks.
