S3E14 : Peter Griffin: Husband, Father... Brother?

While trying to teach Chris about his Irish roots, Peter stumbles upon Nate Griffin, a black man in his family tree. Peter tries to embrace his new-found heritage, but can’t quite get the hang of it. When Lois’ father, Carter Pewtershmidt, sits the Griffin kids down for a look at his family genealogy, a dark secret is uncovered.