blow the coals
To turn a minor issue into a major source of conflict. Likened to coaxing a smoldering flame into a fire by literally blowing on hot coals. Stop trying to blow the coals! There is no tension between Jen and me—you're imagining it! A: "What went wrong last night?" B: "Well, you know Sue, she just kept blowing the coals until everybody was in an all-out fight."