I would get tested for all STDs...a painful bump on your inner lip that is painful could be genital herpes. I know. I have it! Are you in a trusting relationship?
I have a bump on my inner lip its been there for nearly a week and when I touch it I feel alittle painful. Having sexual intercourse it feels painful.
sounds like it could be an ingrown hair. if it is, you could use a warm compress to help soothe it. ;-)