"Jubjub" was derived from the English expression "Lovely jubbly
". "Jubbly" used alone does not mean the same as 'lovely jubbly'. Generally, jubbly is used to describe someone who has done something stupid, silly, clumsy or immature.
ex. "Gow, you're such a jubbly! I can't believe you've locked us out of the car again!"
ex. "We are definitely lost! Why haven't you stopped for directions? Gaa! When did you turn into such a jubbly?"
However, "jubjub" is a shortened, more affectionate derivative of "jubbly". It is used in an endearing fashion, usually with a loved one or child.
-"Aww, come here my little jubjub. Did you fall down and hurt your knee? Poor baby."
-"Come on jubjub. We're gonna be late!"
-"Love you jubjub"