Follow their lead

Most grown-ups join a child's game by taking it over: a better way to build the tower, a rule the game was missing, a question about colours. The child stops playing and starts being taught.

Try the opposite for the first five minutes. Watch what they are doing and do it with them. If the cars are going off the table, your car goes off the table too. Say out loud what you see, not what you think it should be: "Your car is going really fast."

Following is not doing nothing. You are learning the rules of their game, which is the only way to be invited further in.