I use this method a lot, Ruby. It gets the point across better than words.

My daughter would blab our family business to her mother in law and I didn't like that. She was angry with me about telling her it bothered me. Like, "no big deal". It WAS a big deal because her mother-in-law is a gossip.

My daughter had told me something very intimate about her and her husband. I was sure it would be of great interest to her mother in law so I told her I was going to mention it next time I saw her. My daughter about fell over! How could I even think of telling her MIL such a thing?? (actually, I NEVER would)

At that point, I repeated back to her exactly what she said to me when I asked her to stop blabbing our private business to her mother in law.

She was speechless and that was the end of that.

You did well. Words may not have registered with your husband, but your actions did. And you did no harm.