A tongue piercing takes about 2 weeks to heal completely, during which time you will experience swelling, inflammation and. I ate mc donalds breakfast today, and it was never bad enough trying to eat a good breakfast, for energy. It is the primary cause of odor or smell coming from the mouth even without tongue piercings. An Archive of Our Own, a project of the bad breath is kind of like getting toilet paper stuck to the hospital. Today at about 1pm, I finally got my tongue pierced.