Bart and Milhouse torment a tourist named Howell Huser (a parody of television personality Huell Howser), who is then chased out of town by bullies Dolph, Jimbo, and Kearney. Huser is later revealed to be a media personality, and he appears on a network's morning television show warning tourists against visiting Springfield and giving it his lowest rating for any American location (six out of ten). The Springfield tourism business collapses and Mayor Quimby holds an emergency meeting at the town hall. After many senseless suggestions, Lisa suggests that Springfield legalize same-sex marriage to entice visitors to their town. All of Springfield happily agrees with Lisa's idea, even Marge. The town makes a commercial that is broadcast throughout America, convincing people to come to Springfield.
Hundreds of homosexual couples soon arrive to Springfield. However, Reverend Lovejoy insists that the Bible forbids same-sex marriage and refuses to marry any gay couples. After hearing this Mayor Quimby says that Lovejoy is an idiot and while overhearing Quimby's statement that ministers are paid $200 per couple, Homer abandons his opposition to the process and decides to become a minister himself with help from the online "e-Piscopal" Church. He marries every gay couple in town, and then puts up a sign saying "Will marry anyone to anything." While debating the issue with Lovejoy on the television show Smartline, Homer makes a case for gay marriage and mockingly joins the Bible and Lovejoy in matrimony—adding that Lovejoy is the wife and that he owes Homer $200.
Meanwhile, at the Simpson family's home, Patty comes out of the closet as a lesbian, saying that she is in love with a pro golfer named Veronica and asking Homer to perform the ceremony. This makes Marge extremely uncomfortable, even though the evidence was always there. While Homer accepts Patty's sexuality, a furious Marge reveals that she doesn't want her with Veronica and still insists she marries a man. Patty gets angry and points out that Marge acts very "liberal" about the issue but cannot accept her sister's sexuality, and says she hopes to see Marge at her wedding. Before the wedding, Marge accidentally discovers Veronica is actually a man, ironically while Veronica is singing Aerosmith's "Dude (Looks Like a Lady)" while shaving, and because Veronica left the toilet seat up after leaving. Happily she decides to keep quiet about it knowing that Patty will be marrying a man. But Marge is so moved by Patty's heartfelt declaration of love for Veronica during the ceremony that she reveals Veronica's Adam's apple. "Veronica" explains that as the straight Leslie Robin Swisher, he posed as a woman to get onto the LPGA golf tour. He then asks Patty if she'll still marry him, but she declines. Afterwards, Marge reconciles with Patty after telling her that she's learned a lesson and has accepted the fact that Patty's a lesbian; they hug after reconciling. Patty and her other sister, Selma, then go to leave a bag at the airport unattended, as a way to meet security personnel they can date.