Lee Ji-eun, left, head of the Democratic Party of Korea's (DPK) Mapo A district chapter in Seoul, pokes DPK leadership candidate Jung Chung-rae in the cheek during the party's joint campaign speech event for the Chungcheong region, Saturday. After footage of the moment went viral, Lee apologized Tuesday for the gesture but warned of legal action against those alleging that she and Jung were having an affair. Screenshot from YouTube