I posted this in parenting, but I'm kind of desperate to get this figured out and I'm hoping maybe I'll find another guy out there that has dealt with this kind of shit before, whether with their own kid or a niece / nephew / what-the-fuck-ever.

I'm a single father of a six year-old boy, I've technically had my son for most of his life but I've had some extreme difficulty over the past year and a half especially trying to actually get paperwork through the courts. Lately my son's mother has been in one of her cycles where she wants to be "super mom," it usually only lasts for a few months but he's getting older and this time around she's began to try and manipulate him. I knew this shit was coming, it was inevitable. Now that it's here though: it's a pain in the ass. It's usually subtle things; she doesn't tell him that I'm a bad person but from what I'm gathering she leads him into conclusions via what I'm guessing is a "stacked" line of questions.

Example: I leave my son with a friend or his grandfather for an hour or two while I go to the store. I don't know specifically how she does this, but somehow she brings him to the conclusion that any time I leave the house without him he should be scared. I first noticed this when I went to run up the street to the gas station last week and he insisted he come with me because he was scared. When I asked him why he was scared, he said it was because his mother said bad things would happen to him if I ever left him alone. While he didn't specifically say the two were connected, earlier that same week when he had first come back from her house he flipped the fuck out crying and shit when I tried to put him to bed because he was scared of dying. Wtf, right?

Example: My job occasionally requires me to do some work from home. For that night, outside of dinner, my son typically plays video games or watches TV without me. It's not that I ignore him, I'm just occupied with my computer and outside of responses like "Yea that's cool" or answering questions I'm not directly involved with what he's doing.

She's managed to turn this into me neglecting him. He began to take serious offense if I don't stop everything I'm doing to play a video game, play with LEGOs, etc. regardless of what I'm doing instead. Apparently when he's with her she spends every waking moment hovering over him and she's trying to teach him that it's normal, and what I occasionally do is wrong.

I had a girl I was considering going long-term with, his mother was "forwarding" messages through him (as I won't repeat the things she says) and telling him things that were untrue. She didn't want to deal with the drama, began to completely avoid my son as a result, and I eventually broke it off. Not the one for me; I'm cool with that. I just don't want to have to deal with this in the future.

I'm extremely worried. I have a court date coming up and she is now pushing to retain the standing custody agreement if not try to cut me out of his life as much as possible. She's a drug addict; I know she still does drugs like cocaine; the next year of his life will be a mix of instability and neglect if I can't get this agreement finalized or worse if she's successful in her endeavors; this cannot happen. I'm almost completely covered on all my other bases, I just need to have a way to talk to my son without bashing his mother so that he doesn't walk into the courtroom and talk to a representative of the court in the way that she's trying to manipulate him into speaking about me.

I try talking to him, and it seems one issue at a time we're able to work through it... but it seems like every time he comes back there is something new and I only know about the things that he talks to me about. I don't know what else she's planting in his head that he either doesn't mention or, worse still, that she may specifically tell him not to mention to me.

Sorry for the harsh language, but how in the hell do I teach my son not to fall for this crap when he's six years old and I don't want to make his mother sound like a piece of shit? (because let's face it, in the end that helps no one)