Emily found himself stuck, suddenly, on all fours. "Nnnngh," he growled as he tried to get up on his hind-legs, but he just fell forward, finding the balance to be uncomfortable and awkward. Like it or not, Emily walks like a base animal now. The psychological effect of this is immediate and intense.
"How are you doing, boy?" the voice of a man said as Emily's new reality began to sink in. This man was important, he realized, very important. This man was his rider, and Emily realized that he didn't want to get into trouble with his rider. What? It was a strange feeling, this.
Emily had never worried this much about getting into trouble before, not even with his parents. The old Emily, anyhow, had snuck out with boys in the night, occasionally experimented with marijuana, and otherwise gotten into adolescent mischief. While not alarmingly troublesome and really uncommonly manageable and routinely bringing home good grades, the old Emily had had at least some sort of a spine. While unwaveringly pleasant, she had also been independent and free-thinking.
But when he heard the voice of his rider, a much more primitive sense of panic washed over him, and his mind quickly went through a list of things that could get him into trouble, causing his body to go stiff for a moment and his head to bow itself low, his head filled with the servility of a creature that expected to be living at someone else's command for the remainder of his life and had never envisioned any other possibility. Frozen to the spot with self-consciousness, then, and feeling his nakedness intensely, Emily's mind raced in its own tracks as the handsome man approached him.
And was he ever handsome! The man was dressed in a Roman-style military tunic, with the name "Luke" sewn over his right breast, and high lace-up sandals, and while his body was incredibly lean and muscular from the neck-down, he had a broad, cheerful and honest face, with a little youthful scruff that would clearly need to be shaved more often in the future. He was one of those remarkably solid kinds of boys that you would want your daughter to marry, and he walked with a sense of someone approaching a well-trained mount.
As his rider approached him, Emily carefully kept lowering his head to make sure that his eye-level never towered too much over that of his rider, spreading out his forefeet slightly to let his head sink a little lower, lower, and lower still until his chest met the ground, just as his rider confidently strode up next to him and patted his shoulder as if he were an obedient steed. "Have you been a good dragon today?" his rider asked.
"I-I-I...I think I might have been naughty," Emily found himself saying timidly, surprised to hear himself still being able to talk and embarrassed to hear his potentially very masculine voice coming out in such a histrionic whine. In fact, in spite of his mind being altered to accept this man as being his boss, he still had all of his old memories from his human life. He just knew that he was no longer a free creature, instead being a mount. There was no explanation in his head for how this had come to be. It just was, and it was no more weird than being someone's child, except that he could remember a previous life of not constantly feeling ashamed and self-conscious...and visibly sort of aroused by these feelings, which made him blush. He knew that his rider would find his submissive erection very funny and cute, which was a fact that only made him harder until the full shaft stuck out as a flag of surrender.
The human laughed comfortingly, though, and patted Emily on his head, which felt very good. Very VERY good. "Don't worry, boy," he said humorously. "I won't have you gelded this time, but let me tend to that from now on, okay? I don't want you emasculating yourself with those teeth."
Somehow, Emily knew that his rider would never geld him except at greatest extremity, even though it could be done at a word. Emily had no way of knowing this for sure, but some sort of intuition told him that he was very very safe with this man, in an otherwise very unsafe world. Even with no memory of Luke, he felt like a tiny hatchling in the man's presence, as if that were how his life with this man had begun: being held as a tiny, fragile hatchling in the hands of a boy that would govern him for life.
A note on the nature of this reality alteration:
Because a god has interfered in this reality, many other humans have been transformed into obedient (or occasionally rebellious) dragon mounts, and while nobody remembers ever seeing a dragon, they are not considered to be out of the ordinary, now being indispensable parts of most air forces and even being part of a special Marine Special Amphibious Air Cavalry. Dragons always know that they have been transformed, but they are still bonded emotionally to their riders and usually accept their status. The treatment of dragons varies by culture. In more conservative and poor countries, dragons are almost invariably gelded at the drop of a hat, illiterate, and kept in very poor living conditions, but in western democracies, they are treated as family and often educated. In rich but traditional countries, they must follow rigid norms of servility, and in India, they are treated with the same mixture of ceremonial reverence and paternalism as elephants, often being paraded in gaudy jewelry. In liberal bastions, they can speak their minds if they choose to, and it recently made the papers that San Francisco elected one as their mayor, to the gushing delight of egalitarians. This is even a source of nationalism: all countries are certain that their way of handling the new dragons among them is the best way and only way, and children are told that dragons in other countries, except those that are mostly like their own, tend to be either badly abused or constant sources of trouble. More educated families tend to teach their children that other cultures are just as valid as their own. The nature of human discourse is much the same, just with totally gorgeous dragons everywhere.
Oh, and it's totally normal that dragons' sexual needs are met by their humans: those teeth are way too sharp to safely go there (oddly, this folk-wisdom only seems to apply to self-pleasure), but King Kong doesn't have anything on a sexually frustrated dragon, be it male or female. Attracted to them or not, it goes with the territory as much as scraping up their fewmets and bathing them. This doesn't HAVE to ever be mentioned, though. It's like basic hygiene that everybody has to do, although one is allowed to enjoy it, and it's only really discussed openly in boring classes (which certain people have a sudden urge to teach) and very dry textbooks (that are presently being very quickly written).
So what next, bro? Adventure, sex, gay sex, more gay sex, still more gay sex (you're maybe picking up on the author's preference), more petting, whatever's your speed, take your pick, or make something up. Get creative. Dragon-rider themes, yay.