Sometime in the silver age I remember reading a comic and I'm looking for the issue. If I recall correctly, Superman (or Superboy) was alone in space and along comes a 'cute' space alien. They have some fun, but Superman encounters a kryptonite chunk and collapses. As he is about to expire, the being absorbs the poisonous effects, and dies saving our hero. I've done a lot of searching, with no results. Does anyone recall the issue name and number?