What did he do, and how did he do it?

So my cousing did this thing. He started saying I was feeling things when I wasn't buy then I STARTED to! We were talking and then he said, "Like that itch you feel on your right cheek." And then I legit felt an itch on my right cheek. I was confused, but then we continued our conversation. And eventually he continued doing that throughout our conversation, randomly. Eventually he started doing 3 or 4 of them at a time. And every time I felt what he was telling me I was feeling. So what was he doing? What is it called and how can I do that?