A conversation with M (age 5) the other day:

Me: F@ck! (I can’t remember what I was cursing about).

Me: M?  You know that some people think that the word “F@ck” is a bad word, right?

M: Yeah.  I know.

Me: I just wanted to make sure.  I think if you said that word in front on your grandparents, they might get upset.

M: Yeah, I know.

Me: I don’t happen to think that “F@ck” is that terrible, but some people do.

M: I know what the worst word in the whole world is!!

Me: Really?  What?!

M: (whispering in  my ear) When you tell someone, “I don’t love you.”

Me: Yeah.  I think I know what you mean.

M had thrown those words in my face a few times, in anger.  I guess he realized how much it hurts to hear them.