It took him a moment, but he recognized the description Kat had given him. She had described Red to a 'T.' "Yes! Red was very nice to Dean!" His eyes brightened as he reiterated that former point of his, his harmless smile growing wider. "Does Kat know Red?!" Dean's head tilted again, his tail wagging a little more.
It would seem obvious that the people here knew each other in some fashion, especially after what Kat had said to him about her own relations to the others he had met before. But... Well, this was Dean she was speaking to, he was never known for being, smart. Intuitive, endearing, maybe, but never smart.