Saint Joseph, often clarified as Saint Joseph the Carpenter is an important figure in Christian belief as the husband of the virgin Mary and the stepfather of Jesus Christ. According to Christian tradition he was not the biological father of Jesus, but acted as his foster-father and as head of the Holy Family.
In "The Courtship of Stewie's Father," he and Jesus have an argument, resulting in Jesus stating Joseph is not his real father, and calls God, asking if he can live with him. God, in bed with a young woman, claims it is not a good time.
In "Baby Not On Board," he is seen sitting on his couch on his wedding night while noise comes from his bedroom.
In the DVD cut of "Road to the North Pole", Chris singles out his appearance in the mall nativity scene despite not being Jesus' real dad. A follow up cutaway shows a doctor being appalled at the conditions in which the couple are about to give birth in.