Damon was forced through the hole and found himself in a warm, dark tunnel that surrounded his cock body. The jackass backed up a little bit and thrust in harder. Damon was getting rocked back and forth inside female's warm flesh. It was a bliss that Damon had never encountered in his entire human life. He no longer felt sexual pleasure in his cock... he felt sexual pleasure in his whole body, because he was a cock now. Every square inch of himself tingled and sent soothing chills through his inner being and back into the donkey's body down below. A strong heartbeat pounded through Damon, a rhythmic pumping that shook his body and dizzied his mind. It wasn't his own heartbeat, though; it was the donkey's, pumping blood into Damon and keeping him erect.
"Fuck her!" Damon screamed mentally. "Fuck her harder!" He wanted this feeling to continue forever and just get more intense. The donkey received this message as a burst of sexual arousal from his nether regions, which drove him to mate his partner even more furiously.
Damon knew he shouldn't enjoy this. He knew he'd be humiliated when it was over. It was disgusting that he was a penis and that he was now inside the ass end of a jennet. It was dark, wet and smelly. It sucked that the only way he could have any enjoyment now was to pleasure a piece of livestock. His body wasn't his own anymore: he was part of an animal's body now, and this animal would use him at its leisure.
Thrust, thrust, thrust. Pump, pump, pump. The donkey gave Damon more blood, and Damon gave the donkey more pleasure. In and out, in and out. Finally, Damon felt the familiar nausea again. The donkey felt itself passing the point of no return. Seminal glands and groin muscles kicked into action, parts that Damon had no control over, because he was not in charge of this body. All he could do was sit inside his owner's mate and wait for the chunky bursts of semen to gush through him from somewhere down below.
Damon launched every bit of it out of his own swollen front end into his warm fleshy paradise. He was exhausted, starting to get limp again. His owner backed up one more time and Damon was pulled back out into the cool air. The donkey's orgasm had been reached, so Damon wasn't entitled to so much of the donkey's blood or attention anymore. His task, for the moment, was completed.
As the last ounce of erectile strength drained out Damon, he shrank back into the sheath still tasting the cum and the vaginal juices, every bit as disgusted with himself as he had known he would be. He nevertheless found himself looking forward to his master's next round of horniness, knowing that it was the only pleasure he was going to get from now on.