Good advice as well. Thank you. Honestly, how we go at ds about our 'half' is pretty similar to what you stated. I guess you would have to know the lady to know that this is a dig by her. It would have made it easier on me, had she enclosed partial payment, or at least acknowledged that we were only responsible for half. What this appears to be is that they got the bill (which we also did) and turned around and mailed it or a copy to us. My wife just blew it off, because she was already aware of it.
Its not easy to choose my battles with this lady, because she really gets under my skin and has for about 4 years now.
But Im glad to see that most people think that by me getting involved emotionally, is no different from her. Im stayin out of it..We've been sharing parenting for 12 years (shes been here 4)..We know what we're doing.
Thanks for the very good advice, again.