TMI... But need serious advice

So my best friend today was telling me that her lip was bruised because she bit her self on accident and she told me her sore was small . That night she gave her boyfriend head and her sore grew ! And this morning when she showed me it I almost ran her to the ER it looks 10X worse and it's yellow and std looking. Normally little crank sore are white and go away or they don't hurt with drinking water... I don't know and I'm I over reacting? What do you think it is ?