While SpongeBob and Gary are playing tag, Patrick joins in and begins to get better acquainted with the little mollusk. At the end of the day, Gary seems to want to stick with Patrick a while longer, so SpongeBob agrees to let Gary have a sleepover at Patrick's house. The next morning, Gary is still reluctant to leave Patrick, who concludes that Gary wants to be with him and so claims him as his own pet. SpongeBob refuses to believe this, but when Gary is given the choice of who shall be his owner, Gary heads for Patrick. SpongeBob is heartbroken, and out of jealousy, he attempts to find a new pet to show to Gary that he does not need a two-timing snail.
First, SpongeBob gets Rex, a worm, and shows him off to the blissfully unaware Patrick and Gary. SpongeBob extols all the traits that make worms superior to snails, such as their loyalty. Rex promptly illustrates this by abandoning SpongeBob and hitching a ride on a bus. Next, SpongeBob brings home Lary, a snail with a terrible temperament. SpongeBob bends over backward to accommodate Lary, even giving up his own bed to the picky snail, but Lary's unceasing viciousness leaves SpongeBob forlorn. Even the anatomically correct snail, Jerry, can't fill the hole in SpongeBob's heart.
Patrick, accompanied by Gary, stops by SpongeBob's house to do some laundry. In desperation, SpongeBob begs and pleads with Gary, offering him all manner of gifts and privileges if only he'll come back. Patrick patronizingly tells SpongeBob to let it go, that Gary has already made his choice. Gary, meanwhile, crawls into the washing machine after Patrick's shorts. SpongeBob and Patrick watch, Patrick angry that Gary apparently just likes him for his fashion sense. SpongeBob, however, realizes that all along Gary had only wanted a cookie left in Patrick's pocket. As SpongeBob and Gary, now satiated and reunited, go outside for a walk, a heartbroken and devastated Patrick stares after them and shouts, "Gary? I thought what we had was special!"
When the camera zooms in on SpongeBob thinking, Patrick is saying "Blah, Blah, Blah" in the background. When the camera zooms out Patrick is speaking normally again, but when SpongeBob leaves Patrick's rock, he says "Blah, Blah, Blah" again.
SpongeBob, in a throwaway joke, reveals that he has another pet snail, "Jerry," a photo-realistic land snail.
SpongeBob reminds Gary that he took care of him when his eyeballs were sore. Closed-captions alternate between "sore" and "tore" in different airings.
A smaller version of SpongeBob's wringer can be seen when Patrick is placing his basket of clothes on the table.
In the beginning, SpongeBob is playing tag with Gary. When he runs up his house, an extra window is seen next to the upstairs window. The extra window reappears at the beginning of the scene where SpongeBob introduces Rex.
Rex, SpongeBob's pet worm leaves on a bus. In early airings, this bus had obvious jellyfishers on it. If it stayed this way permanently, then it would make this the final episode to feature a bus full of jellyfishers.
The face SpongeBob makes when he says "Who's a good boy?!" to Rex can be seen on various SpongeBob licensed products, including the newer packages of Kraft SpongeBob SquarePants Macaroni and Cheese. It is accompanied by the slogan, "grin and square it!"