I totttttally hear you. I don't like kids, and everyone that knows me, knows I don't like kids. I have a 3 yr old nephew and 9 month old niece and I don't even want them there either. I tried to find an 18+ resort but there were none in my price range, in the area I wanted, which was a huge bummer. Luckily of my invited guests, there are only 5 kids (including my sister's), and I've made it known that I'd like them to all stay behind, so that the parents can also enjoy a week to themselves, without time contraints or early bedtimes or whatever. (Taking kids on a vacation just sounds like a nightmare). Anyway, here's to hoping they don't come. And I'll also be stating that my at home reception is also adults only. Also kids just have no business being anywhere near a swim up bar, and if the parents are there, they'll bring them along, and then all of a sudden it's a baby party.
Also, as a side note - if I were staying at an 18+ resort, and I saw people bringing children onto the property (even for a wedding) and the hotel allowed this to happen, I would be choked! Adults only means adults only. Good luck!