Motercycyclist dropping his right foot

I was driving home from work this evening and noticed a motorbike behind so I moved to the right and allowed the moterbike to pass by. He appeared to acknowledge my good nature by dropping his right leg to the ground. He did the same thing as he passed out the next 4 cars in front of me, either this or his was underwear itching him.

For my effort of looking in my review mirror and pulling over, I would like a more imaginative response like a big wave of better still a big smiley face to light up on his back. Yes a big smiley face is what I need for my effort. They would also get a better response from other drivers.

So lookout for a smiley face.