It's up to YOU to break the cycle. He pokes, you poke back, he pokes, etc., and on and on.
Let him poke... and don't respond. Not at all. He'll probably poke again, and maybe again. Eventually, his small brain is going to register that he isn't getting the expected reaction. Then he will do something different. Don't know what it will be, but you will have changed the dynamic.
You can do it. But you have to want to. You have to go against you instinct. You have to accept that he can think whatever he wants, and there isn't a thing you can do about it. And then stop trying.
