It begins with Andy and Danny stuffing their mouths with marshmallows. Andy pauses, spits his marshmallows out, and says that the audience is probably wondering why he is about to put a dog-licked marshmallow into his mouth. The answer is that he doesn't want to lose to Danny.
It all started when Andy blew a sausage up like a balloon and put it in the lunch. Then, Lik and Leech walked over and claimed it was their table. Andy and Danny apologized and left, with Andy even giving them his lunch. The blown-up sausage then popped on them. Andy then plans to do some serious pranking on April Fools' Day. Danny is more interested in playing Feed Your Face, but Andy is not interested, and too busy. However, he didn't want to lose to Danny, so they scoffed their faces with fries. Andy won, and then Lori came up. She was a bit grossed out, but fascinated and gave the boys invites to her birthday. Andy wanted to go, but Lori has also invited some scholarly, formal youth club members and has disallowed "stupid" pranks. Andy promised no pranks but then saw that the party was on April Fools' Day. In Andy's room, he lamented to Danny that April Fools' Day was like his Christmas and he got to be Santa. Danny didn't know why Lori would not like Andy's pranks, and both thought the party sounded boring.
At the party, the fancy scholars were playing golf. Danny was getting cynical, which he does when he's bored. Lori, in a blue dress, welcomed them inside. Lori's dad April Fools joked that they had run out of sparkling grape juice. Andy thought this was a weak joke, and Danny was still bored, then Lori went off to help her mother. Andy saw a youth club member and wanted to give him a wedgie. He then spied Lori's presents and added his: a book on palm reading which he'd modified to make it look like his own palms. Lori's dad entered and told Andy about the practical joke about wrapping up Lori's presents. Andy and Danny thought that was a weak joke. Lori gave the boys marshmallows and Mr Mackney ate one, planning to eat twenty. Andy bet he could fit thirty marshmallows in his mouth, and Danny bet he could fit sixty in his. They then played Feed Your Face, one marshmallow at a time. At four gooey chewies, Lori and the president of the club Sadie came in. Andy didn't speak, but Sadie told them about the youth club that was called H.A.P.P.Y. (High Achieving Proper Peppy Youth Club). Lori's mother then called Lori over to fetch more salt, and the boys had hidden in the closet and gotten up to eight gooey chewies. They left when Lori's dad opened the closet and continued playing, but the Mackney family dog licked the marshmallows, that's where the viewers left off.
Lori and Sadie arrive, laughing, and Lori thanks Andy for the book. Andy sneezes and puts the gooey chewies in his pocket. Lori asks to read Andy's right hand. They see the resemblance and leave. The boys then continue to play. They then play golf outside and Mush delivers pizza. Andy finds it hard to talk, and Mush mishears "I got a mouthful of marshmallows" for "I'm feeling mellow". Mush wants Andy to flirt with Lori and Sadie. Lori offers pizza. Andy likes it but finds it awkward with his mouthful. Lori asks Andy to blow her candles out because she has a cold. Andy blows them out. The adults go upstairs and Sadie makes a toast. They then play spin the bottle and the bottle lands on Andy, so Lori has to kiss him and Andy has to swallow, but he sneezes his food all over the others. Lori thinks Andy caught her cold. Danny celebrates his win and marshmallows fall out of his mouth, making Lori and the H.A.P.P.Y. people mad. Lori then kisses him, and it turns out that hiring the H.A.P.P.Ys was an elaborate April Fools' joke. Then, Andy, Danny, and Mr Mackney play Gooey Chewies.