The kids came up with the joke:

“Do you like fish sticks?” (Pronounced like “fish dicks”)

Then, when the person said yes, they’d call them a gay fish.

The joke becomes a meme on the show, but Kanye West doesn’t get it, despite having it explained to him. He thinks the joke is directed at him personally, and does actual scientific research to find out why people think he is a gay fish. At the end of the episode, he accepts his fate, and decides to live as a gay fish (complete with a catchy autotuned song.)