Do not use bleach or other chemicals on your lips or elsewhere on your body. As for the fly, your brief encounter should not be any problem. Your body is set up to fight all kinds of germs and foreign matter. Of course, always visit with your doctor for any symptoms.
Hello, I would not worry, I think that flys have landed on many of us, and nothing has ever happened. One thing, using bleach or harsh chemicals on your body is not safe, it could be worse than having the fly land on you. I am sure you are fine, but if you have any disturbing symptoms, then check with you GP.