As for this: "When I went outside, he hung around long enough to angrily tell me that I should not be demonizing everyone at his house, especially since I wasn't with S14 at the BMX track, where x feels he should be supervised. He yelled, "Weren't you the one who grew up with that kid who killed animals?" "
WHAT A CREEP!!!
This I think is worth bringing up at the next session and/or emailing the C about. It is NOT OK for him to use these sessions as assault-opportunities. What B.S. Thinking about it more, I really think you should definitely email the C. Those sessions are supposed to be safe spaces for the two of you to work together. He needs to be called on that crap and it needs to be agreed that it won't happen again. But let C determine the strategy here...
And, in any case, next time: "This conversation needs to happen with C, save it for next time." Then, walk away. Don't give him the power. Don't engage with him when he pulls this crap. What a tragic figure he cuts, and tragic figures really are not attractive life partners. Yuck.
