How to use idioms to describe such people?

Hide the knife in a smile, force a smile, and pretend to smile even if you don't smile.

I don't keep my word, but I don't keep my word.

A smiling tiger smiles obsequiously, threatens his shoulders, deceives his heart, deceives his heart and is treacherous.

Have it both ways is a two-way street, but he is obsessed with this situation.

Call a deer a horse, be foolish and not crazy, be happy to help others, be kind and hypocritical, and deceive others with false facts!

Do to others what you don't want them to do to you!

Lies, lies, false vinegar, lies, lies.

Self-deception and insincere rhetoric make colors bluff.