I’d definitely talk to him first and just say that you feel bothered when he threatens with court so you just want to have make sure things are fair on both sides and you want to come up with a fair parenting plan with him that he feels comfortable with. Tell him it’s better for both of you because it will have to be followed if things were to ever not be ok with you both.

Like previous poster says sometimes that's just the way it goes. I wouldn't give him a heads up though. Sometimes those things take a while to come together and it sounds like it will just give him extra anxiety that he doesn't need.

May I ask how he is being unstable and what he needs help with? If not that’s totally okay.. but regarding him getting papers and being blindsided, unfortunately it’s just the way it goes. Even when I get some in the mail or served or vise verse to my child’s father it kind of always just has a negative vibe to it. One thing me and my child’s father do though is try our hardest to talk things out, and we’ve discussed how we can’t let getting served, court and lawyers affect us to the point that they affect our son. He’s pretty unstable too when it comes to his personal life so we handle that through mediation and if necessary court. But never between us privately if that makes sense. We separate ourselves and our son vs the issues.