Didn't "Batman: The Animated Series" and "Batman Beyond" imply that a relationship between Barbara and Bruce occurred at some point?
They sure did. I remember being grossed out at the time because she used to be Dick's girlfriend. Beyond the whole "Bros before hos," betrayal there's also the whole, "You don't stick your dick in the same hole your son did," creepy incest vibe. Though Bruce may have a loophole since Dick is adopted, though he may have a bigger loophole since in the TAS universe Dick was just his ward. But the emotional bond is father/son so it's just nasty in my mind.