<human>: Summarize the given text in a few sentences.

Sorry if title is misleading but this is my situation which is making me furious and hurt.

background , my ex left me for another guy many years ago , no problems there. After a couple of years they decide to relocate around 400 miles away and take my kids.
From then the relationship with ione of the kids has gone despite me doing almost everything to repair or heal or stop it happening.

Anyways , still to this day 7 or 8 years later my ex is so vindictive and viscous. So always hassle where seeing my kids is involved.

Thats not the issue here , what is a new one is my own sister and my own mother being contacted by my ex to arrange some visits.
They dont tell me about any of this and i think thats wrong.
Personally i want my kids to see all my family and thats sort of a no brainer as they say.
But should it not be me that deals with it? 
I would never dream of contacting her sister or family and organising things.
i would feel that is divisive and wrong , i would thank the ex for suggesting it and being agreeable and say i would contact the other parent and take it from there.
Now ive fallen out with my family over it as i feel they have been insensitive considering the history and rude for not telling me and hurtful for doing this behind my back.
Am i wrong?
<bot>: Mandatory summary/question! Should an EX partner deal with sensitive issues with the inlaws over parenting without the other parents knowledge.