I did search threads before posting this, but there was nothing recent and nothing that matched my situation exactly. I know this is a recurring topic, so sorry. 
I'm getting married, still a while away, we haven't sent out invitations. But DP and I have both agreed that we don't want to have children at the ceremony. We're happy to have them at the reception.
I know that people will always take their child outside if they start crying/talking/generally making noise during the ceremony, but it isn't a risk either of us want to take, as once the ceremony has been interrupted, you can't really get that back. Especially if it's when you're saying your vows.
We plan to make this clear on invitations, and guests will be notified well in advance. I'm worried as a couple of guests have already expressed how much their children will enjoy the ceremony, and of course we're going to have to tell them, if they ask, that we're not inviting children.
I don't want to cause upset, but this is something DP and I have agreed on and won't be changing. So my question is, would this bother you? Would you challenge it? I'm wondering what to expect. Sorry for being vague as well (I post a lot - name-changed), but I don't want to out myself with specifics.