Might even think that you have totally lost it. But, if you are wild and crazy enough, he should come over and investigate. Ignore him for a few moments after he gets to you, then suddenly notice he is there and make a big to-do about him joining the party. Then run back and keep running the course. Here is a method introduced by Sharon Nelson.
Theory being it takes two to play.
This is also a dominance statement, showing who actually is in control. The solution is so simple but hard to do. Look at the ceiling if you have to. Your friends will tell you what is going on with your dog. Continue to ignore and very slowly walk off.