"Hey hay there Jimmy at stud, I am Mister Carter, the true owner of the magic lamp and of its genie. I Trust from what my Genie told me of you and your wish to become a donkey Jack, that you have had your fun these past fifteen years. I wish to alert you to remember who as what you were, as only you, the Genie, and me know who you were before becoming this..., this beast.
Well your parents who have forgotten you even existed. You got your life of lust and sensual freedom. A very smart Jackass you are in comparison to the common donkey Jacks in this your home, your corral.
I must agree with my Genie, as he does have his art of changing human flesh to beastly flesh.
My Genie sends you his best wishes, and asked me to tell you he would be willing to give you two free wishes, if your donkey cock is worn sore from living the lifestyle of a stud male animal?
To give a look at yourself, I would say my Genie is correct in what he told of how you asked of him, to gain a brown furred hide, a whip of a tail, four legs, and hoofs.
You think about your two wishes, and I shall return here in a week and then you can scrawl in the corral dirt you wants!"
That all said, and Jimmy stood there having a boner, his mind going wild with ideas of changing his body and lifestyle to being something a bit more fun than a donkey stud male.