Thin end of the wedge

Translation of "thin end of the wedge" into Russian

первая ласточка

Allowing minor rule-breaking can be the thin end of the wedge for more serious offenses.

Разрешение на мелкие нарушения может стать первой ласточкой для более серьезных проступков.

A small or seemingly minor action or event that is likely to lead to larger, more significant, and often undesirable consequences.