"Hmph." 

Ace scoffed, watching as a few people drooled over you since you were in a dancer outfit in Alabasta. Unfortunately, the dancer outfit was all that was available, so you had no choice. However, he wasn't complaining. The unwanted attention is what made him protective (and jealous).

"Hey buddy. This lovely individual right here is mine and not for your eyes to see." He grumbled, pulling you a bit behind him with a scowl at the person.

And Ace still denies that he's jealous.