The Simpsons - Season 24 Episode 22 -
Dangers on a Train
Marge mistakes Sassy Madison, a swinging-type website, for Dolly Madison, a cupcake site, not realizing it’s a destination for married people seeking liaisons. On the site, she meets the charming Ben, who pursues her after they learn they share mutual love of TV series Upton Rectory.
Meanwhile, Bart and Homer obtain a small steam train from the now closed down Itchy & Scratchy Land.