don't give (something) a second thought

Do not give some situation or decision pause for any doubt, concern, or further consideration. When an opportunity this good comes along, don't give it a second thought—take it before it slips away. A: "I'm so sorry for breaking that vase!" B: "Oh, don't worry, it was just a cheap old thing. Don't give it a second thought!" Don't give her comments a second thought—she's just trying to hurt your feelings because she's jealous, that's all.