I think because you didn't write the NC letter and you don't have an IM, he would be irate with you not emailing him.
I can't help but think about if he wanted to do this co-parenting session for future purposes...like he can document that he tried to be a good father in case you D.
You can email him and just say whether or not you want to go. If not, you can say you don't think the counseling is necessary. or you can just go for co-parenting purpses. do you have a schedule written in place already or not?
me,34 exH,34 S,16 months S:3/31/09-left for OW started DBing 10/09 d final: sometime 10/10 current: http://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2022856&page=1 met in 2004