MammaKit, this post brings me to tears. I remember, so clearly, my youngest son asking if we were ever going to get together again (he was about 5yrs.). That told me how long the kids harbor fantasies of their parents reuniting I remember holding him on my lap and talking to him---then going into the bathroom and drying behind closed doors. I also, did not want to be reunited with that man for even one millisecond!!
My point, is that seeing the two of you together (esp. so early on) might just fuel false hopes for the kids. I think it might be harder for the younger ones to comprehend the whole thing--what the reality is than the older ones. Now that they are grown and really know what their dad is like (very narcissistic), they completely appreciate that they did not have to live with him full-time.
Hope this helps....
dandylion