WOW, Mystik- your H is totally being insensitive! He is clueless! I need to be honest here- I think it is totally appropriate for you to set a boundary and tell him that you don't want to discuss the OC in any form. That you want nothing to do with the baby.
As for your son bringing up being a big brother, is there a way you could divert him to your H? Saying something like...I am sure you are excited, S! Why don't you talk to daddy about it next time you see him!
I don't know if that is too cold...but you are validating your S' need to talk yet training him that he can talk about it with the father of the baby, not you. Yikes--hope this isn't too harsh sounding!
What does your IC tell you to do in order to deal with this OC??? (other child)
And good job ignoring the texts from your H...technically you aren't breaking NC when you talk about things related to your S schedule. That personal stuff about his clothes, etc., was not business! So it was perfect for you to ignore.
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