Sometimes it's a name given to a person who has avoided all possible bad things that could have come their way. Therefore someone who is
jealous of someone's outcome of a particular
set of events either because they were
smart or lucky could be called a Bastard.
Jim is a prude, he doesn't drink smoke or fuck.... therfore he doesn't have a shot liver, broken heart, depression, lung
cancer or a sore itchy groin from having his dick in lots of vagina....
Jim is a smart guy who has avoided all of the crap people go through.... I'm jealous; therefore he is bastard.