Because of the controversy over gay marriage in the United States of America in the past, this episode had a Parental Discretion Advised warning before the show, the first time for The Simpsons. The episode was also rated TV-14 for suggestive dialogue (D) and sexual situations (S) because of this.
In Australia, this episode was rated an M and included a "parental advisory: adult themes" warning for the same reason above.
At the end, Lisa points out that Homer's marriage business is now over, with Bart asking why. This is a reference to every harebrained scheme Homer had concocted in the past, only to have it end for one reason or another, whereas Bart's "Why?" points out that nothing really got Homer to put an end to his business even though nothing bad happened to make Homer end it, yet in the episode after he is back working at the Springfield Nuclear Power Plant.
Patty Bouvier officially comes out of the closet as a lesbian in this episode after being in the closet and dropping her hints of her sexual orientation for the first 344 episodes.
At the end of the episode the following characters are lined up at Homer's chapel: Captain McCallister (marrying a Dainty Lady figure), Comic Book Guy (marrying a life-sized cardboard cutout of Booberlla), and Ralph Wiggum (marrying a tiger).
The song playing in the background as the gay couples celebrate their togetherness in Springfield is a parody of several Harry Belafonte songs, particularly "Jamaica Farewell" and his signature "Banana Boat Song". Although Belafonte is straight, his name is dropped in the line "I'm gonna marry my Harry in Springfield town."
Marge discovering that Veronica is a man is a reference to Chris Hillard discovering that Mrs. Doubtfire is his father in disguise from Mrs. Doubtfire.
Marriage laws in the United States-prior to the 2015 Oberfell V. Hodges Supreme Court decision-were chosen by states, not cities.
Although Homer stopped being anti-gay in "Homer's Phobia", and even lived together with two openly homosexual men in "Three Gays of the Condo", he still can be seen holding a sign "death before gay marriage".
Reverend Lovejoy is unable to cite the book in the Bible condemning homosexuality (allegedly Genesis, Leviticus and others), yet in "Homer the Heretic", he is able to cite a completely random Bible verse of Homer's choosing from memory (Matthew 21:17).