That's it slave. Now lie on your back and spread your legs as far as you can.
Put an ice cube up your ass, and listen carefully: you're going to keep fucking yourself, at least one pump into your ass per second. You must keep going until the ice cube melts. This time, obviously, you will not know when it has melted until you check. If you check and it has not melted, shove another ice cube up there and start again. If it has melted, you may continue.
But let's mix things up a little: I want you to stroke yourself while you fuck yourself, and though you may not falter with your fucking, you may stroke at your own pace. Make sure you edge at least three times before the ice cube melts, however.