Pull the rug out from under you

The phrase "pull the rug out from under you" is an idiomatic expression that means to suddenly remove support, stability, or security, usually when someone is least expecting it. It implies a disruptive action that causes someone to lose their advantage, footing, or comfort. This can be a metaphorical reference to physically pulling a rug from someone's feet, which would lead to them stumbling or falling. The phrase is often used to describe situations where trust or expectations are betrayed, plans are disrupted, or someone's position is undermined without warning.