Is this childish?

So my soon to be ex and I have two kids. 1 and 2 and our one year old has a well check on the 25th and I texted him to let him know and he told me I no longer have that obligation when your gonna have the kids. So grow up a little bit and just face it. Is it childish that I told him about it and asked if he was going to be able to make it? This whole thing sucks and he’s so negative and mean about everything like I’m the enemy when he’s the one who’s stepping out. 😔