Pulling her hands away, Sam stared up at Ty. Grinning, Ty said.
"Lay down on your back." Instantly, Sam complied, her tits jiggling and wobbling the whole way.
Kneeling down in front of Sam, Ty gently spread her legs, exposing her pussy, before lining up his hefty cock. Looking at Sam, he slowly pushed into her, both teens shuddering at the new sensations. Sam winced as Ty broke her hymen, but the pain was soon overwhelmed with pleasure. Quickly, Ty began to thrust faster and faster, both his and Sam's boobs jiggling and bouncing with each thrust. Looking down at his, then Sam's breasts, he still thought they weren't big enough. Making up his mind, he quickly wished.
"I wish that my breasts will grow till they are F cups, while Sam's grow till they are E cups. I wish that both of our breasts will double in sensitivity because of this growth."
Quickly, their boobs started to expand even more, their new weight pulling and tugging at their chests. They soon stopped at "impressively large" sized mounds of flesh.
Soon, they both cried out in climax, helped by their new, larger and more sensitive boobs. Ty buried himself up to the hilt in Sam's womanhood, long thick spurts of cum filling Sam up.
Moments later, Ty pulled out, spent. After a quick wish, they were both cleaned up and cuddling next to each other.
"That was great!" Sam cried. "Can we do it again?"
"In a bit," Ty responded. "Boys have a longer 'recharge' time in between bouts of sex than girls. I can speed mine up if you want."
"YES!"
"OK, but can we try something else this time please? I mean, these huge boobs are great and all, but I'm still I guy. I like my dick more, and it hasn't been changed all that much."
"Sure, what did you have in mind?" Sam asked, shifting around so she was sitting cross legged in front of him.
"Well, have you ever seen horses mate?"
"Yeah, my uncle owns a farm. I've seen stallions lay on top of mares before. Is that what you are talking about?"
"Yes," Ty said, starting to grin. "Can you see what I want to do?"
"Oh!" Sam cried in understanding. You want to change to two horse and play that way?"
"Not quite," Ty responded. "You see, many guys are jealous of horses and their massive endowments compared to humans. I'm no different, but I can do something about it. Would you like to see?"
"Alright!"
"OK," Ty said. "Here we go.I wish that my cock and balls will grow and change into the genitals of a prize stud stallion, like the ones I had previously, starting when I stop speaking for more than 5 seconds. I also wish that I will be flaccid during and after the change until I speak the words 'Hung like a horse.'"
Exactly five seconds later, he was overcome with the familiar feeling of this change. His cock suddenly deflated down to it's 3" flaccid state, before it started to extend, getting longer and thicker than his forearm. As it grew, it pulled up towards his stomach, his foreskin attaching itself to the skin there and completely covering his still-growing cock. Still, it grew, as did his newly formed sheath, only stopping shortly before his belly-button was enveloped in the soft, leathery flesh. Next, his scrotum proceeded to get much larger, and hang about 1/2 to 3-4 of the way to his knees. By now, his balls looked almost comically small in his massive scrotum. That soon changed, however, as his balls started expanding to the size of average cantaloupes. Finally, the skin on and around his crotch darkened to black, before being covered by short, soft, ebony fur.
The whole time, Sam stared in awe as her master's genitals shifted and grew before her eyes.
Looking at Sam, Ty felt his now massive balls churn in their furry sack at the sight of her bare body and exposed pussy. Before he did anything though, he considered his options.