Lil is invited to a party but Phil is not because he is "S-I" (socially inept) and Lil moves out of the twins bedroom of many years and into the office/exercise area. Phil gets upset. Chuckie tries to skip the President's Fitness Test. Chuckie hides in the bathroom and breaks the pipes. Lil is at the party but the tweenagers are making fun of Phil so they go to the "Twin Canyon Resort" at the end and together too.
Angelica or Susie were not invited to the party (Whether they aren't friends, don't know each other, or because they are older).
It is revealed that in this episode that Lil is two minutes older than Phil.
Kimi, Angelica and Susie didn't appear in this episode (though the former is mentioned) ergo making it the first episode where one or more main characters are absent.
This is the only episode without an ending tagline.
At one point in this episode, when Dil tries to be Phil's new twin brother, he buys himself and Phil shirts identical to the ones Phil and Lil wore throughout Rugrats.
When Phil looks at a bunch of photographs of him and his twin, a photo of him and Lil as Rugrats is shown. This is the first time the twins are shown as Rugrats in All Grown Up as well as the first time a reference to Rugrats in All Grown Up is made.