Well, I'm probably going to get a lot of blow back from this, but I'm telling you what I would do.
The Co-parenting session is not about your R, it's about how to parent your child together. There is no 'going dark' when it comes to your child's wellbeing. That being said, you have got to lay this on the table. Tell the C that you want to be heard before anything else is discussed in the session and you want to be heard without interuption. Your H seems to have a lot of blaming and blah blah blah going on but you never say a word. How is that being an advocate for your child? Bottom line, tell the C that you feel there is NO co-parenting going on. Tell her about the appointment with the C that STBXH skipped, tell her about pulling up to the house and OW being there and ask how you should handle that when your S14 is with you and sees this behavior. Your STBXH has to be hit over the head with how his actions are affecting his son.
Aliens hae ZERO clue!
I had a mind blowing experience when talking to my XH about the situation he put our son in. I asked him what kind of example of manhood and responsibility he was setting for our son. His response, "I'm not here to set an example." WTH????? Excuse me? That is what parents do! Our children learn from our examples. If we demonstrate love, responsibiliy, support and integrity then that is more likely what they will model. If we show them moral bankruptcy, lies, manipulation, and disrespect to those around us then that is possibly the path we put them on.
I remember just sitting there dumbfounded by the statement. A while later I reminded him of what he said and he looked shocked. He thought I was making it up! I asked him if I had ever lied to him or misrepresentd the truth in any way. He had to honestly say no. I then described the scene in detail and the reason he had been there and he remembered it then. He just shook his head and said he had no idea what he had been thinking.
When some of them wake up from their fog, they can't believe some of the things they did and said!
Call him on it now in the safe, supportive environment of the C office. You may be able to redirect the handling of your son.
T19 M15 S19 XH47 M43 bomb12/4/07 PA5/07 S12/26/07 D final 11/17/08 Back together with no defined R 05/2010 confused....to say the least!!!