He has them both blow him.

"Alright girls, I want you both to kneel before me," Luffy ordered the two.

They both complied, falling to their knees. They looked up at him as Alvida grinned, "I like where this is going..."

"Oh yeah," Luffy grinned, stepping a bit closer. "Vivi, take out my dick."

Vivi nodded, a faint blush on her face as she started to work on his pants. She pulled them down, making his erection spring out and slap her cheek.

Both girls stared at it for about a minute, but did nothing, awaiting his further instruction. He smiled at their restraint, before saying, "Both of you, start pleasuring me with your mouths."

"I almost started to think you'd never ask," Alvida smiled, licking his balls as Vivi drew her tongue along his shaft.

Luffy sighed in contentment as they got to work, Vivi looking up eagerly as she ran her tongue repeatedly over his length as Alvida took one of his balls into her mouth to suck. Vivi then followed up by sliding her mouth onto his shaft, and closed her eyes as she pushed her head forward, allowing his length to slip right in towards the back of her throat.

He began to pet their heads as Vivi bobbed her head while Alvida continued to suck on his ball and caressed his thigh. She then let his ball slip from her mouth with an audible pop, and placed a hand on Vivi's back, prompting her to pull off, looking at her.

Wordlessly, they agreed to swap, and Alvida licked his tip as she gave him a sultry look, and Vivi groped his scrotum as she licked at it. Luffy gave another moan as Alvida enveloped his cock in her mouth, quickly bobbing her head back and forth as he noticed her mouth was even more slippery than Vivi's. No doubt due to her Devil Fruit.

He began to instinctively pump his hips as they continued their efforts to get him off, switching up a few more times as both kept gazing at him longingly. Soon enough, his length began to throb as he rapidly approached his climax.