Catholic Heaven is Heaven for Catholics. Its is a noisy place full of Irish, Italian, and Mexican people (the three largest Catholic ancestries in the United States).
When Bart's and Homer's converted to Catholicism, Marge imagined herself in Heaven. St. Peter told her to go to Protestant Heaven. Unfortunately, she noticed that Bart and Homer are entertaining in Catholic Heaven, with Mexicans dancing salsa, Italians kissing and drinking wine at a dinner table, Irish drinking beer and fighting, and Homer and Bart playing piñata. Then everybody in Catholic Heaven started dancing Irish traditional dance. Marge was sad that she couldn't be with her family and decided to talk with Jesus about her problem, but then she saw him entertaining in Catholic Heaven with Bart and Homer.