Jailbait is a term usually applied to teen girls under the age of consent that the user of the term finds sexually attractive.
They are so desirable sexually that you would persue sexual relations with them regardless of the legal penalties that might be involved.
So, in classic blaming the victim terms, these girls are "baiting" you to wind up in jail, as if you are some zombified, helpless, spellbound victim that must satisfy your desire.
More like spun sugar.