On her chest.

Kenji fell back against the wall with a roar. His cock popped out of Shoko's mouth a moment before the first rope of semen splashed on her turquoise turtleneck sweater. Caught off guard, three more jets of cum splattered her chest before she realized that her top was already ruined so she just held his cock and let him spray his seed on her. She had expected him to be like most of her male patients and be finished after releasing less than a teaspoon of semen but instead Kenji continued for almost a minute.

"Gah!" Kenji gasped, thrusting his hip forward to jettison the last spurt from his balls onto the doctor's cum-soaked sweater. Shoko stroked his shaft and squeezed his balls, trying to milk more jizz from him. When she was satisfied that he could give no more she wrapped her lips around the tip of his cock, licked it clean, and gave it a playful kiss.

"I am sorry about your sweater, Dr. Sugimoto!" he apologized profusely when he came to his senses and realized that her top was painted with his sticky cream.

"No need to apologize. The cost of taking it to the dry cleaner is worth knowing that you can still ejaculate," Shoko replied as she stood up to remove her white lab coat so she could pull the sticky sweater over her head. Kenji could not take his eyes off of her leopard pattern bra that barely held in her huge, soft tits.

"I am sorry," he muttered, looking down. She was not sure if he was still apologizing for the sweater or him staring at her breasts.

"Very impressive, Mr. Kataoka," the young doctor smiled at his still rock-hard erection twitching excitedly. "Now we know you can ejaculate, at least with fellatio. So we can rule out the physical cause of obstruction ejaculatory ducts."

Kenji nodded weakly, still recovering from his first blowjob.

"That said, we still need to know if you can ejaculate from other methods of stimulation," Shoko stated matter-of-factly.

"What do you mean other methods, Dr. Sugimoto?" he asked with curiosity.

Shoko smiled at his perked interest.