spare (one) (something)
To not force one to listen to or engage in something, especially that which is tedious, dull, or unpleasant. I can see that you understand what you did wrong, so I'll spare you a lecture about it. Spare us the lurid details, James.
spare someone something
to exempt someone from having to listen to or experience something. I'll spare you the details and get to the point. Please, spare me the story and tell me what you want.