After discovering a shocking truth about Beast’s birthday, Harley throws him an epic party that causes a rift between the twins.
- Jenna Ortega as Harley Diaz
- Ronni Hawk as Rachel Diaz
- Isaak Presley as Ethan Diaz
- Kayla Maisonet as Georgie Diaz
- Nicolas Bechtel as Lewie Diaz
- Malachi Barton as Beast Diaz
- Cerina Vincent as Suzy Diaz
- Joe Nieves as Tom Diaz
- First appearance of Wyatt
- This episode is similar to the plot of the Liv & Maddie episode "Sweet-16-a-Rooney".
- Lewie and Beast get into fight in this episode that tears them apart.
- Harley goes up into the attic but soon worries the twins will tell her parents that she has been up there.
- Dumpster Jack makes a appearance from the twins favorite tv show in this eposide.
- This episode reveals that Lewie and Beast were born on different days and their parents never told them.
- In the first episode, Lewie says that he was born 90 seconds before Beast, but when they find their birth certificates they say that Lewie was born at 11:58 pm and Beast was born at 12:03 am, which actually makes them an hour and 3 minutes apart not 90 seconds apart.
- May 23, 2017 (Israel)
- June 24, 2017 (Brazil)
- June 27, 2017 (Hungary)
| To view the Stuck in the Beast-day Party gallery, click here.