I have another stroke challenge for you. I will decide how many strokes you can do, and what tempo. Each time I will give you a little test, to see if you have cum. You will be made to stroke over one of my heels. If at any time you need to forfeit, you will cum in my shoe. Be warned, there will be a punishment for cumming early. Let's hope you have some stamina, or you will be tasting your thick specimen from my shoe. Throughout the clip, I will change the tempo of your jerking. I will change the amounts of strokes you can do, or the time you can stroke for. I want your cock to be aching, and dripping for me. However, you mustn't cum until I give you permission.