I dunno, I see what you are trying to say, but I think there are ways to answer that positively WITHOUT hurting their feelings.
My kids ask that kind of stuff too, of course. I usually answer with, "That is SO BEAUTIFUL! Wow!" And a great big hug. They don't even notice that I didn't actually answer their question, they just wanted a response.
This morning my 5.5 yr old tried to make us breakfast. She brought me and DH each a pear, a carrot, a string cheese, and a yogurt. It was so sweet.
But I can't eat that in the morning b/c I'm pregnant and have a finicky stomach. So I just thanked her profusely and gave her lots of hugs and appreciation, and when she looked up and me and said "Aren't you gonna eat it mama?" I honestly said, "Aw baby, I wish I could but my tummy is so upset from the new baby, I can only eat eggs in the morning. But THANK YOU SO MUCH!"
I can't think of any instance where I've felt I had no way to answer them other than to lie.