Peter's Two Dads
Family Guy Season 5 Episode 10 (02/11/07)
After Peter's father, Francis dies, Thelma tells Peter that his real father is in Ireland. Peter goes to visit his father, who turns out to be the town drunk, and challenges him to a drinking contest to prove his paternity. Meanwhile, Lois spanks Stewie when he misbehaves. Stewie realizes he likes being spanked and acts out in anyway he can to get punished.