I say "huh. I hadn't heard that one. Let me look it up. .... Ohh no, that turned out to be fake. It's getting so hard to tell these days. Just the other day I was reading..." And then start rambling about another topic. It prevents them from sitting with the uncomfortable feeling of being an idiot.
I believe that there's an inverse relationship between number of consecutive emoji and ability to hold a conversation. Doubly so if it's four clowns.