Why the hell wouldn't he?

"You sure you want it?" he asked her, only for her to smirk from behind the veil, and trail a hand down his torso, ending with her index fingertip pressed against the tip of the tent in his shorts, making him gasped as he realized just how sensitive his erection was to the touch of another.

"Master... I want your pleasure more than anything else I have ever desired in my life," she assured him. When he nodded, she pulled her veil aside, and floated herself down a bit, so her upper body was horizontally suspended at his waist level. She immediately pulled down his shorts, and took a moment to stare at his cock. It was... magnificent. Due to her knowledge as a genie, she knew it was only a bit above average, objectively speaking, but this wasn't just a penis to her. It was her Master's penis. She could stare at it forever, and never get tired of it. But right now, she had a task to get to.

Her tongue slid out from between her lips as she began to lick at his cock head. He jolted as the sensations already started to overwhelm him. She smirked in delight, knowing he was enjoying her efforts as she gently grasped his cock, and began to stroke the length slowly.

Her lips parted and she wrapped them around the head of his shaft. "Mmm," she moaned, before moving her hands to his thighs, and began to lower her head, until she had him to the root in her mouth.

Luffy grit his teeth and stretched out his hands to grab trees ten feet away to steady himself as Hancock began to bob her head up and down his length. "Oh... This might actually better than eating meat..." he panted. He could hardly believe he was saying it, but the sensations in his manhood didn't lie.

He then felt something building up, unable to last long due to his inexperience. "Ugh, I'm about to cum..." he gasped, able to tell what it was due to his previous wish.

This only made Hancock bob her head with greater fervor. She didn't stop until Luffy cried out, and came, his salty essence filling her mouth. She kept her lips wrapped around his head, letting every spurt hit her tongue. Once his member was spent, she pulled off with an audible pop, and looked up at Luffy with her lips pursed. Then, just to excite him further, she opened her mouth, showing him his seed was still in there, before closing it again, swallowing, then she opened her mouth again, showing him she had swallowed all of it.

"...wow..." Luffy panted as his member softened.