Pair of Kings - Season 1 - Eps 21: Journey to the Center of Mt. Spew
It's the kings' birthday and for their royal present, they each get one wish that will come true. Right before blowing out the candles, Boomer learns that Brady has been bragging to the entire island that he is the older twin. Boomer uses his wish to find out the truth about who was born first, while Brady's wish is that Mikayla compliments him all day. Boomer travels to the center of Mt. Spew to meet with the volcano's Oracle and learn who is the older king, but the younger brother will no longer be co-king if it is known who the older brother is. So Brady, Mikayla, and Mason chase after Boomer.
About Pair of Kings

Title: Pair of Kings
First Air Date: 2010-09-10
Last Air Date: 2013-02-18
Status: Ended
Rating: 8/10 (from 109 votes)
Language: EN
Seasons: 3
Total Episodes: 69
Network: Disney XD
Genres: Action & Adventure, Comedy, Sci-Fi & Fantasy, Family
Production Companies: It's a Laugh Productions
Synopsis
Brady and Boomer, 16-year-old fraternal twins, are typical teens being raised by relatives in Chicago. But when the Royal Secretary to the Throne of the Island of Kinkou, arrives to inform the boys of their lineage, their lives change drastically. Now, Brady and Boomer must relocate and claim the throne as joint Kings of the island.
Cast

Doc Shaw
Boome Parker

Adam Hicks
Boz Parker

Kelsey Asbille
Mikayla Makoola

Ryan Ochoa
Lanny Parker

Geno Segers
Mason Makoola