The Simpsons Episode 17.10 Homer's Paternity Coot

The Simpson family receives a long lost letter and discovers Abe may not be Homer's real father. Homer tracks down the author of the letter and takes a DNA test to prove that his biological father is Mason Fairbanks, a British treasure hunter. While the rest of the family awkwardly attempts to continue their relationship with Abe, Homer is injured while helping Mason salvage a sunken treasure. Homer's touch with mortality drives him back to Abe where he discovers that Abe switched the DNA test because he thought his son was happier with Mason.