Michael Denny and the Denny Singers

We're guessing that's Michael, bottom right

Musical act that really hates the idea of trunk people getting married. You know what trunk people are, right? They're people who have a special trunk that allows them to have sex with both men and women. Anyway, they exist in some variant of Earth, according to a snippet of "Rixty Business," a largely improvised episode of animated comedy Rick & Morty (first aired 14 March 2014). And Michael Denny and the Denny Singers hate the idea of them getting married.