Luffy doesn't ask him if he's sure. Sanji wouldn't tell him to do something he wasn't sure he could handle. It doesn't stop the flush deepening across his cheeks though, eyes half-lidded and breath quick. His nerves tingle with pleasure, with desire. Sanji is mesmerizing where he is -- taking care of Luffy in that same way he always does. In the way Luffy knows he can count on, whether it's food or... this.

He licks his lips and slides his hand from Sanji's hair to rest against the back of his neck to tug him in. "... Okay, Sanji," he murmurs, his own voice lower and rougher.