Grandma Janice visits the Rooney family to present her granddaughter Liv with the "Porcupine of the Year Award." But, Maddie grows suspicious that it's Janice's twin, Great-Aunt Hillary who's actually visiting and pulling a switcheroo.
Maddie is preparing laundry to be washed, when suddenly Liv barges in and announces that Grandma Janice is visiting the Rooney family to present her granddaughter Liv with the "Porcupine of the Year Award." In two separate confessionals, both twins brag about Grandma Janice's accomplishments as an Olympic diver and a wildlife photographer. Karen has a confessional of her own, where she explains that her daughters have a bond with their grandmother because she and their Great Aunt Hilary are also twins, something she herself is lacking. Maddie is surprised that Grandma Janice is presenting Liv with an award, because she assumed she was the favorite grandchild.
At school, Joey, notices that Artie's minions are approaching him. Realizing Artie himself is nearby, he tries and fails to get away. Artie proposes to arrange a party at his house to watch the passing of the McGilroy-Mimen JK-113 Comet, a.k.a. the "Lover's Comet," in the hopes of getting girls to fall in love with them, and use Joey's sophisticated telescope. According to legend, whoever a person is with during the comet's apex is destined to be their true love. Upon her arrival at the Rooney household, Maddie and Parker are puzzled by the fact that she only hugged Liv, and didn't give Parker $20 for being the cute one of the family. Later she finds that Grandma doesn't want to play a game of basketball with her. Maddie grows suspicious that it's Janice's twin, Great-Aunt Hillary who's actually visiting and pulling a switcheroo. Karen tries to convince her that this isn't the case, and she's just acting "crazy pants."
Back at Ridgewood High Joey and Artie discuss invitations for girls for the Lover's Comet party. Both boys spot Alex who is in the halls reading two books at once. When Joey mentions his past attempts at a relationship with her Artie shoves him over to get him to invite her to the party. Not seeing anything unpleasant about the invitation, she accepts his offer. Later Artie spots Samantha, a student in the drama club who Joey also recognizes. Artie summons his minions to push him towards her and invite her to the party, with a fledgling attempt at Shakespearian English. Samantha, who is much better at it than he is, accepts the offer. Unexpectedly, Aubrey walks behind the two boys and tells them she knows about the upcoming party. Joey invites her to the party as well, and she accepts the invitation too.
At home, Maddie serves tea and crepe suzette to Karen and who she suspects isn't Grandma Janice, because this was what she had with her in a previous visit. Parker comes out with a pair of pajamas decorated with ducklings, bunny slippers and a blanket on one shoulder and talks in baby talk in an attempt to act cutesy and get $20 from her, but it doesn't work this time either. Later that night at the party, Joey and Artie inspect Joey's telescope which actually has a female voice machine announcing the proximity of the comet. He walks though the house and encounters the three invited girls, one of which could become his soulmate. But just when he thinks nothing could possible go wrong for him, Willow strolls through the door and reveals that she was invited. Just then, Artie and his minions reveal that he was the one who invited her, and he intends to snag either Alex, Samantha or Aubrey from him.
The same night at school, Maddie talks "Grandma Janice" into joining he in a pre-game warm-up ritual, that her Great-Aunt Hilary wouldn't be as familiar with. She performs the routine perfectly with her, but Maddie's not convinced. Just then Karen accidently reveals that she was their great aunt all along. Once the cover-up is exposed, Great Aunt Hilary reveals that Grandma Janice's flight out of Africa was stalled by bad weather. All three decide to maintain their charade for the benefit of Liv.
Joey tries to keep Willow from joining the party, and she become frustrated and takes off. As he returns to the family back yard, Artie tries to flirt with Alex, who rebuffs his advances and tells him that Joey invited her to watch the comet. Overhearing this, Samantha reveals that she was invited by Joey, and Aubrey does the same almost immediately. Just as Joey arrives outside, he sees all three accusing him of cheating on them, and decide to leave together.
Still posing as Grandma Janice, Great Aunt Hilary presents the award to Liv. As she begins her speech, the real Grandma Janice finally arrives in the school gym. Karen, Maddie and Hilary explain Janice's situation, and despite taking offense about twins playing a switcheroo on other twins, Liv forgives them. Parker, however is still upset that Janice never gave him $20 for his cuteness while she was impersonating his grandmother, and admits that while she originally planned to do so, she ended up spending the money on lottery tickets, which he found impressive.
With nobody but Joey, Artie and his minions at the party, Artie gloats over his act of sabotage, and leaves with his minions. As his telescope continues to track the comet, Willow returns claiming that she had left her coat behind. In reality, she never brought a coat in the first place, and was just taking advantage of the approaching apex of the comet with Joey. Just then, the rest of the Rooney family arrives at the house and Grandma Janice calls them an adorable couple, and credits the comet with the marriage to their grandfather, something that excites Willow even further as much as it terrifies Joey.
- Dove Cameron as Liv and Maddie Rooney
- Joey Bragg as Joey Rooney
- Tenzing Norgay Trainor as Parker Rooney
- Kali Rocha as Karen Rooney
- Benjamin King as Pete Rooney
- Emmy Buckner as Liv #2
- Shelby Wulfert as Maddie #2
- Jessica Marie Garcia as Willow
- Jimmy Bellinger as Artie Smalls
Special Guest Star
- Patty Duke was famous for playing look-alike cousins Patty and Cathy Lane on the 1963-66 ABC sitcom The Patty Duke Show.
- Many say Liv & Maddie is a modern-day successor to The Patty Duke Show.
- This episode was written by real-life twin Sylvia Green.
- This episode did not air in August on Disney Channel by references. SPARF-a-Ronney and Champ-a-Rooney did air though.
- Although it was shot for Season 2, the episode premiered in Season 3, which explains why the characters looked so much younger than they did back in season 2.
- At the end Maddie says "What a crazy pair!" which is a reference to a line the Patty and Cathy show's theme song.
- Janice and Hilary thought they were their grandma's favorite.
- This episode was Grandma Janice's only appearance because of Patty Duke's death on March 29, 2016.
- This was Patty Duke's final television role before her death.
- The comet's prediction of Joey and Willow ending up together as they were both under the apex comes true by the end of the season.
- Willow's hair is much longer than it was in Cowbell-A-Rooney. It couldn't have grown that fast. This is due to the fact that the episode was originally intended for Season 2.
| To view the Grandma-A-Rooney gallery, click here.