Trixie catches Muffin sucking her thumb on the way to Bluey and Bingo’s house. She tells Muffin to stop because it’s bad for her teeth, but Muffin refuses. As a result, Trixie puts the “cone of shame” on Muffin. When they arrive, Bluey and Bingo greet them and notice Muffin’s cone. Trixie explains that she’ll take it off if Muffin stops sucking her thumb.
The girls try to play a game of Sandwich Shop, but Muffin’s cone keeps getting in the way. She bumps into things and mixes up items because she can’t see properly. Bluey suggests they talk to Trixie about taking the cone off. Meanwhile, Trixie is in the kitchen with Chilli, who offers her tortilla chips. Trixie declines at first, saying she’s trying to eat healthy, but then gives in and eats some chips anyway. The girls come into the kitchen and ask Trixie to take Muffin’s cone off, promising that Muffin won’t suck her thumb. However, as soon as the cone is off, Muffin starts sucking her thumb again.
Muffin explains that she doesn’t know why she sucks her thumb and walks off, feeling sad. Chilli talks to Bluey and Bingo, and they decide to come up with games that Muffin can play despite her cone. They use the cone as a prop, pretending it’s a wedding dress, a traffic cone, a ballerina, and a flower. Later, Chilli finds out that Trixie ate all the chips, and Trixie admits that she and Muffin both have no self-control. Trixie decides to take Muffin’s cone off, and they head home. The episode ends with Stripe taking Muffin to her cousins’ house, where she starts sucking her thumb again and ends up wearing the cone once more, prompting the girls to cheer “CONE OF SHAME!”