While Timmy Is preparing for his parent's anniversary, Timmy inadvertently causes a fight between Cosmo and Wanda that escalates to Cosmo running home to live with his mother. Cosmo's mommy, who never liked Wanda, uses the fight as a chance to break the Godparents up. And Cosmo, the consummate only child and Mama's boy, is helpless before his mama’s onslaught. Timmy must travel with Wanda to Fairy World, rescue Cosmo from his mother, get Cosmo and Wanda back together and still get back to Earth in time to give his parents their Anniversary gift.
It is the anniversary of both Timmy's real parents, and his fairy godparents. While the former gain a blindfold and roller skates, the latter (specifically Cosmo) has prepared for their 9895th anniversary by turning Timmy's room into Styrofoam. But when Wanda returns from the meaningless task that Timmy sent her out to do (trying to teach a cat some tricks, only to end up clawed), she is in a seemingly angry mood. So when Cosmo puckers his lips for an Anniversary kiss, she refuses and unleashes the cat on him. Cosmo poofs back to his mother, Mama Cosma, in tears and unaware that the 9895th anniversary was supposed to be the "False Anger" anniversary, which Wanda was acting out.
Also, Mama Cosma is completely unaware that Cosmo and Wanda are married, but knew they were in a relationship before. When Cosmo knocks at his mother's door, she is glad that he's no longer with Wanda. Meanwhile, Timmy and Wanda arrive in Fairy World. But as he is about to make a wish, others fairies gather, though Wanda makes them back off. She then slumps down, exhausted, for getting a human to Fairy World alone takes a lot of magic, meaning that he be stuck where he is unless his godparents make up. Luckily, she has enough strength to poof them to Mama Cosma's house and they come just as Mama Cosma is attempting to set up Cosmo with two fairies named Star and Twinkle and feeding him, "I Rather Dislike Wanda Cookies".
The two godparents then have a magical brawl, turning each other into different things, such as a hippo or baby. When Timmy accidentally gets turned into a toilet, he wishes for both of them to stop. He tries to remind them that they love each other and is certain that they'd love each other all over again. Mama Cosma takes the claim literally and puts everyone on "The Fairy Dating Game", hosted by Cupid. Whomever Cosmo chooses gets hit with Cupid's magic arrows that eternally will make someone fall in love. After wishing himself back to normal, Timmy fears what could happen if he doesn't prepare his parents' anniversary dinner; at the moment on Earth, his mother has become quite testy and she eats a part of the table, telling Mr. Turner that if she didn't get what she wanted, she would start eating everything in the house.
Unfortunately, Mama Cosma has bribed Cupid to try and make sure that Cosmo does not fall in love with Wanda. But the initial attempts fail, as Wanda clears up the misunderstanding about their anniversary and admitting how funny it was how she transformed him into a literal example of a Mama's Boy, which Cosmo agrees with. Seeing that they are beginning to fall in love again, Mama Cosma calls for a commercial break and gives more money to Cupid to double his efforts. Realizing that he may be stuck in Fairy World forever, Timmy brings up the love arrows to reunite his godparents. However, Cosmo bends down to pick up a nickel, causing the arrow to bounce off his chair and hit Cupid, causing him to fall in love with Mama Cosma. Taking Cupid's place, Timmy gives Cosmo a question card that practically surmised the entire episode and to ask what Wanda would say for the misunderstanding. Star and Twinkle are unable to answer the question, but Wanda gives a heartfelt apology to Cosmo, then the curtain pulls back and Cosmo pushes away Star and Twinkle to reunite with his wife.
As the game show ends, Mama Cosma cries out no, forbidding her son's choice of bride. Confused, Cosmo asks his mother why she hates his wife. Mama Cosma explains that it's not just because she hates Wanda, but she practically dislikes anyone who takes her son away from her. That's why she wanted him to marry Star or Twinkle, who was revealed to be robots, programmed to do whatever she says, unlike Wanda. As she proceeds to insult Wanda, Cosmo quickly intervenes. He admits that he isn't bright, confused by big words and has the attention span of a rodent, but Wanda loves him anyway and that she makes him happy. But that doesn't deter Mama Cosma, who promises to try harder to split the couple apart. We then see Cupid who is still under the effect of the Love Arrow. She tells them they haven't heard the last of her and she will be back before getting chased away by Cupid.
Returning to Earth, Timmy cooks up a casserole, which his mother doesn't like, until he hits her with a love arrow. He then uses another on his father, who proclaims his love for his wife, only to back off from her monstrous behaviour, claiming he can wait. Nearly, in their fishbowl, Timmy's godparents celebrate their anniversary with the kiss they both missed before, only for Cosmo to spontaneously forget it was their anniversary as the episode ends.