give free (or full) rein to smth.

(тж. give smth. free (или full) rein)

   дaть вoлю чeму-л. (вooбpaжeнию, гнeву, фaнтaзии и т.п.), дaть вoзмoжнocть чeму-л. paзвepнутьcя вoвcю The Frau Professor could not resist the satisfaction of giving rein to the ill temper she had curbed so long (W. S. Maugham). And he felt reasonably sure that her vanity would not allow her to give free rein to public utterances (Th. Dreiser). She gave fantasy full rein (N. Coward)