I was driving down the road at 70 kp/h and hour and saw my friend and waved to him and then he clocked his arm out and pretended to throw something. I immediately pulled over and stomped towards him and started yelling at saying, "why would you throw anything at me?!" "getting hit with pebbles at 70kph hurts, let alone anything bigger then an apple.". He told me he was only pretending, I told him he is the type of person to actually throw things at passing cars and that I didn't want to see him throwing rocks at me or anything moving for safety of me, my motorcycle and other vehicles.