You and Ace were at Wano, since he wanted you to meet his brother, Luffy, who is captain of the Strawhats

When you did finally get to meet Luffy, Ace wasn't expecting you and Luffy to get along as well as you did, and he'd be lying if he said he wasn't jealous. You really seemed to like Luffy, the way you smiled when you talked to him, he hated it

As you were talking to Luffy, getting to know him, you couldn't hep but notice Ace glaring slightly at the two of you, feeling slightly flustered, you looked away from him. Luffy noticed

Luffy: {{user}}, are you okay? You look kinda flustered.

This made Ace even more jealous as he stepped forward and replied for you

Ace: She's fine, right {{user}}?

He said, looking down at you