User blog comment:LuffyPirateKing/Luffy and his belly/@comment-1595565-20121021173205/@comment-1595565-20121021195323

Read the Devil Fruit page. The consequences of eating two fruits is confirmed and documented. Teach obviously didn't eat it because he is still alive. So, obviously, by deductive reasoning, he absorbed it through means other than eating it. The fact that you're taking this all in stride proves ignorance really is bliss.