"When they go home, they sharpen pencils, eat kale and dream up homework assignments," Buster, Arthur's rabbit friend says. "They don't even sleep! They just go into low-power mode and watch documentaries."
They then think Mr. Ratburn is marrying a woman named Patty (voiced by Jane Lynch), who he is spotted having lunch with... The kids think he looks miserable with her so they decide to go to the wedding to stop it. However, once they arrive they see that Patty is Mr. Ratburn's sister, and he's marrying a man.
"…big props for celebrating love and fearlessly exampling to a young audience all types of relationships," one Twitter user wrote.
"MR RATBURN IS GAY HELLO!!" another wrote. "HE GOT MARRIED!!"
"Well, can't say that I expected that. Not only that Arthur is still going, but that Mr. Ratburn is openly gay. I have to applaud the writers for doing this. Bravo!"