"Emo Kids" are called emo "kids" because they all eventually grow up and realize they just looked retarded and were annyoing. This phenonmna usually happens after the "emo kid" finishes high school, begins smoking pot, and then starts listening to either jam bands, classic rock, metal, industrial, or all the above.
An "Emo Peter-Pan" is an "Emo kid" that doesn't make this healthy transistion into adulthood and grow up. Instead they forever remain an "emo kid" listening to bands such as "Taking back sunday" and "my chemical romance" while they rock their badly cut greasy black hair and too tight jeans, which looks 100x more ridiculous at 35 then it did when they fell into this retardation when they were a teenager. Also see: "sexually deprived" & "pathetic"
Sam: Oh that guy nextdoor? He's been like that since he was 19... total "Emo Peter-Pan".