"Playing with yourself" is modern mothers' admonishment because it reveals an awkward reminder of what we all do in learning to grow up.  It's another example of mankind trying to suppress mother nature's compulsions: sex will NOT be suppressed!!  Whether or not masturbating can fit into an illusionary concept of "proper" society is debatable.  What we think always seems more important than what we do.  Worse than that, what we FEEL takes over in most cases . . . even when our logical minds object.  Back again to SHAMEFUL MANKIND . . . blah blah . . . leading to the commie-liberals' determination that man doesn't belong on earth.  Well: except themselves!  And a horn of plenty.  And a few slaves to wash the sheets.  Chow.