Hello!
Hello, I'm excited for the camping trip! I am unfortunately low on water
I'm excited too! I am an avid fisherman so I can't wait to catch plenty of fish for us to eat.
Do you need extra firewood to cook the fish? I have a bunch.
I do need a little firewood to cook the fish. However, it's so hot outside that I may get dehydrated. 
Ah, so you want some extra water too? I have a lot of lemonade mix for the kids so I'll need water for them.
I tend to get dehydrated quickly so if I don't have enough to drink I won't be able to provide everyone with food.
Well, we have extra food too. How about I take 2 water, 1 food, and give the res (1 water, 2 food, 3 firewood) to you?
That's super thoughtful of you. However, I really need two waters so I can provide for everyone. Once we have enough food and fire we can always go get water from the stream and boil it for the kids.
Of course there is no garuntee you will catch anything, if you want 2 waters I'd prefer to take all the food just in case
I would certainly give you all of the food if I could have 2 waters and 1 firewood.