coparenting and trying to remain positive

by to

i have a toddler who's being put in the middle of uneccessary conflict. have been co parenting for a while now. my ex moved in a bf shortly after our seperation. since he's been with her, my relationship with her has taken a nose dive and we can't coparent at all.
He's a horrible influence on our son and badmouths me to our son, and she doesn't stop it. ie he sends our son to me on visits to tell me im a liar,etc, "by their own admission" tells my son im stupid, etc. have tried to address the issues with her and request she have him stop, all i get is lies that i am responsible for making our son say these horrible things and somehow its my fault, when it's obvious, "by their own admission" they are doing this.

in addition, it appears she is on a smearing campaign to destroy my relationship w her family in the form of exaggerating stories to them to make them not like me.

used to just ignore their behavior but wondering if i should bring this to the attn of her family, also is it proper to bring this to mom's attn as i have been and politely ask her to speak w step about the abuse, i know it hasn't done any good but would it be better to say nothing at all when dealing w these types of persons?