H.D.
My son has a language delay due to his Autism but we do social stories for concepts he doesn't grasp. I'm assuming your son sees a speech therapist? Ask them to write you a simple social story to show the importance of what is true and what isn't. My son does best with "real" pictures vs the P.E.C.S cards but either can work in a pinch. So in your case, I'd take a picture of you looking really sad so you can ad that to his social story. GL!