burst someone's bubble

Verb

 * 1)  To disillusion; to disabuse someone of a false notion or rationalization that has grown comfortable.

Translations

 * Czech: brát iluze, kazit radost
 * French:, casser le mythe
 * German: jemandem seine Illusionen rauben, jemandem seine Illusionen zerstören
 * Portuguese: cortar o barato de alguém