What does it mean to be 'bubbly' in the book Uglies and Pretties?

i dont get it. In the book they are like 'not very bubbly-making.' huh? what does it mean? and also, in Pretties when Tally jumps from the hot airballon and losesher hoverboard, where are Zane and FAusto? I like the book, but its confusing. AN answer would really help!