I usually don't reply if it doesn't involve the kids.Yesterday I got a weird one that kind of sounded like it was about the kids,then went off into wth is this and why did u text me?
I just stopped and she's learned that when I stop,I'm done.
X "Are you taking your lunch to the ballgame tomorrow?The kids are having hotdogs and chips.
Therefore,S9 can't eat anything there"
Me"I figured that.I'll pack his lunch and bring it"
X "It still technically my time and I'll pack his lunch.
Me "Whatever"
X "I have to follow the rules" (Going through divorce)
Me (Scratching my head trying to figure this one out)

S9 is going on a field trip and I'm going with him and his class.He can't eat alot of foods,so he'll need to take his.I still can't figure out why she even bothered to text about it if she was going to pack his lunch anyway.
It all depends on you.If you don't want to communicate,don't.If you do,do it by email or text only.