People inviting their children along without asking!

[Sixparrotspullingupcarrots]

We are planning a surprise party for a friend's birthday next weekend. It's a 4 hour trip on a boat followed by a meal in a quite posh (ie not super child friendly) restaurant from 6pm onwards. We have invited about 30 people and we are paying for the whole thing, including the meal. We decided not to invite any children because the birthday girl doesn't know the children and we didn't want to then invite swathes of other kids.

One couple asked if their children aged 3 and 5 could come. We said it was ok for them to come on the boat trip. Now they're coming to the meal too, although we specifically said that they could only come on the boat. Her parents live locally so it's not like they don't have any childcare at all.

This weekend we received an email from them inquiring as to whether the boat could stop along the way in case their (uninvited) children get bored and want to get off!

AIBU or are they taking the piss?

I don't think it's unreasonable to invite people with kids to a child free event- that would mean that you would never get invited anywhere that wasn't suitable for children- cue a thread about how your child free friends always drift away when you have had kids... You should not have made an exception for them. It's a bit late to take back the words now, but I think you should say sorry, have asked the boat and it's no kids. They are not 10 years old- they are toddlers!

If the lady who is having this birthday surprise arranged for her doesn't know anyone's children, and isn't bringing any of her own, then it's not unreasonable at all to have an adult-only trip and meal. If she doesn't even have children of her own then what were you thinking of saying yes in the first place?

If others who are going will have paid for childcare then you are in danger of massively pissing them off when they arrive to find that others have brought their children.
I think if you want to arrange a child-free event once in a while that's absolutely fine, even loving parents can enjoy some child-free time. That might mean that some parents won't come, that's fine as well, their choice. Nobody should feel put out about it. Having children present changes the dynamics, I'm not saying that's good or bad, just different.
I can't see a problem here really. The parents have given you the perfect opportunity to ring them up and say that, now they mention that their children might get bored they've got a point. It's an adult event, their children will be sure to get bored and with the benefit of hindsight you think it will be much better if they don't come to the boat trip or the meal. In fact, you realise now that it wasn't really fair on birthday-lady and the others coming to have considered agreeing to it in the first place. If that means the parents drop out, no problem.

You can't assume their family can baby sit.

But, I'd feel irritated if I'd arranged for my relatively sensible older ones not to go, to find that there were some tinies coming.

I don't think people can assume the kids will be screeching round the boat though. We did take dd1 to places that weren't necessarily child friendly (not an invited thing, but by ourselves) because we knew that she would be well behaved and quiet. We wouldn't have considered taking the other two because they wouldn't be.