in a weak moment
During a moment in which one fails to have the discipline to act according to one's principles or better judgment and instead does something regrettable. I admit that, in a weak moment, I accepted a bribe to allow development to proceed without proper safety measures in place. I'm so sorry I cheated on you. I gave in to my base desires in a weak moment, and I'm ashamed of what I did. Our nicotine lozenges help you control your cravings in weak moments.
weak moment, in a
At a time of weakness or little resistance, as in In a weak moment I agreed to let our son rent a truck.