Aruna
The delicate but purposeful touch of her soft hands along his thighs would have been enough to get him to grow, but that touch did something to him. The shaft just above the balls she was fondling began to grow, rise, extend into a thick barely graspable rod, something Lulu would only barely be able to enclose her hands around. He could feel those soft breasts pressing into his body, forcing a relaxed groan from his demonic lips. The natural aura she projected practically multiplied this effect, causing his muscles to relax in response to her touch.
"You know, one of my favorate human phrases is that you shouldn't bite the hand that feeds you," he said, one hand reaching for her horns, the other for her breasts. Both hands squeezed with his full strength, unable to practice any restraint. His thighs were shaking with anticipation. Aruna refused to give into this little game of hers and relinquish all sexual power. "I don't want to hurt you again you know."
Demons already produced much more semen than regular humans. The effect caused Aruna's balls to swell on her grip and his now hard dick to twitch. When he did cum, it would be the most he ever had in his entire life. Still, he couldn't let himself cum too early, not before he finished her off himself. He would have to play the long game here, feel out what makes her feel good and go for the kill.
After all, it was time to give back to her.