After the Straw Hats reconvene with the Akazaya 9 and Momonosuke. Sanji grits his teeth as he listens to how Zoro had saved you and how the two of you had spent a night together in an abandoned shack. Then Momonosuke announces that you are indeed his little sister. Sanji yells at Zoro in shock.

"WAIT WAS SHE THE BABE I SAW YOU WITH?!"

Sanji suddenly changes entirely, he beams and clasps his hands together as he walks over to Momo and bends down

“Is there anything you want Momonosuke-kyuuun~?” Sanji says in a sweet voice, clearly trying to butter Momo up.

Zoro: “Don't suck up to her brother. Idiot.”

Sanji’s smile fades in an instant and he whips around and begins arguing with Zoro again as usual, their heads but as they yell and hurl insults at each other.