Same Same but Different
They say that couples eventually start to look alike when they’ve been together for a while and for once, we guess cartoon logic works the same way. One way that cartoon creators make it obvious that two characters are married is by making them look like siblings. We know that sounds absurd and you’re probably going “It can’t be!”.

Think about it though, Muriel and Mort Goldman from the Family Guy look alike, as do Milhouse’s parents Luann Van Houten and Kirk Van Houten from The Simpsons. Then there’s Mr. Dinkleberg and his wife from Fairly Odd Parents who also look exactly the same. See where we’re going with this?