Bite the Hand That Feeds You

To act badly toward someone who has helped you

Steal the Show

To attract the most attention and praise at an event

Steal Someone's Heart

To cause someone to fall in love with you

Go Bananas

To become very excited, angry, or crazy

Sky Is the Limit

There is no upper limit to what can be achieved

Don't Judge a Book by Its Cover

Do not judge something by its appearance alone