STEAL ONE'S THUNDER

{v. phr.} To do or say something, intentionally or not, that another person has planned to say or do. * /Fred intended to nominate Bill for president, but John got up first and stole Fred's thunder./ * /Mary was going to sing "Oh! Susanna," but Ellen did it first and Mary said Ellen had stolen her thunder./ * /Smith heard that Jones was going to offer a new law which people wanted, so he himself proposed the law first, stealing Jones' thunder./