Skating on thin ice- Carmen has been late for class three times. If it happens once more, she will be suspended. Carmen is skating on thin ice!
Doing something considered risky, dangerous, or uncertain.
Go fly a kite- Jason was tapping his pencil against the table. He noticed that it was annoying Amy, so he kept doing it. Amy told him to go fly a kite.
A phrase used to tell someone to go away or stop irritating you.
Don't count your chickens before they hatch- Mark never practices, but he still thinks he will make the basketball team easily. His friend tells him, "don't count your chickens before they hatch."
Do not make plans expecting something good to happen because it might not, and you will be disappointed.