Sanji gives him a pleased smile for that answer. Luffy is indulging him and spoiling him because, even if it doesn't always look like it at first glance, Sanji is at his happiest when soaking up physical affection. He's truly the definition of 'never enough hugs as a kid'.

Not one for making his captain wait any longer, He starts quickly undressing after that kiss, his head tilted as a smile spreads further on his lips. Sanji isn't a shy man by any means, but the way Luffy is so openly casual with his affection has him feeling a little giddy.

"What can I say? I like the sounds you make when I get my hands on you."  It's his turn to lean in and press a kiss to the other man's lips—quick but meaningful. 

He has to take a step back after that, to walk out of his pants and stand there simply wearing his navy boxers and a minute later, not even those. Rather than dropping the rest of his clothes on the floor, Sanji gathers them and folds them over the nearest surface. He turns the showers on so the water will be hot by the time they step inside it. His attention goes back to Luffy, a hand reaching out for him.

"Come here, beautiful."