Fold, crumple or somethingelse.

It would depend on whether the child were folding or crumpling the sticker. Have you looked up the words here: www.onelook.com?

"Fold" = neat and tidy action
"Crumple" = crunch up and squash - a more destructive action

Thank you for your help.

My question is what the words or phrases you would use in a situation where your child does the thing I described.

If the child were folding the sticker, I'd say "Don't fold it".
If the child were crumpling the sticker, I'd say "Don't crumple it".

I don't know what you mean by 'half fold'.

Thank you again.

half fold, i meant fold in half. Actually, when you once fold a sticker, because of stickiness it stuck in the half-folded state unless you want to fold more from then on. And also Ii couldn't sure if "fold" is appropriate, since you don't actually fold it, but the stickiness just attracts each other's ends.

onizohalf fold, i meant fold in half.

Then say "Don't fold it".