This might sound weird, but I want to lick a kid's hand
Why would you lick a kid's hand? I can understand if they are your kids, but it seems very weird otherwise.
I think it would feel good.
Most people will be grossed out if you told them you wanted to lick their hand. If it's just a fantasy, it's harmless.
Right, I would never engage in any behavior that wasn't consensual. THAT would be really gross.
As long as it's just a fantasy and you understand how people would respond, I don't see the harm. You might even run into a consenting adult someday who shares the same fantasy.