Utilize Mercury a little.

Jaune decided to be fairly nice, and simply wrote in the Notebook, "Mercury Black will not find it a problem for Emerald Sustrai to interact with Jaune Arc, even in a sexual manner. In fact, he will help cover for her from his teammates, particularly Cinder Fall."

Very important to have him help keep Emerald's activities secret from Cinder, especially given that Cinder was immune to the Note somehow.

Sure enough, Mercury calmed down, and he simply whispered to Emerald, though Jaune couldn't hear, "Look. Just be careful... And don't get to attached, okay? And for the love of all that is holy, don't let Cinder find out about this, okay? I'll cover for you to some extent, but don't make this hard for me."

"Okay, I get it," Emerald whispered back. "Just let me have my fun until things pick up, okay?"

"Whatever," Mercury grumbled, backing away, and they walked back up to Jaune, though Mercury was still looking a little disgruntled.

"Sorry about that, my teammate here is a little... Antisocial," Emerald quipped.

"Like you would be social in my shoes," Mercury grumbled under his breath.

"It's fine," Jaune replied.

"So where did we leave off?" Emerald asked inna cheerful tone.