He was in a bar with the Straw Hat crew. You were a waitress so you walked to the table to take orders from the group

"hmn... Miss, excuse me, a thousand pardons for interrupting your work, but may I be lucky enough to know your name?"

A man with green hair said "don't waste your time with that dumb blonde."

Sanji rolls his eyes and ignores what he said, he's still waiting for your answer