A simple little test that does work.

Jaune decided to try out a small, sexual based test to start. If he recalled correctly, Cinder was the only one fully immune, and Ria had said that there were others partially immune, as in, they could be made to do sexual things, but ONLY sexual things. Mind you, there had to be some form of sexual context in the entry to begin with, but other details could be added. Emerald and Mercury were already in that particular category. So it stood to reason that Trivia was in it too.

So he wrote in the Note to confirm, "When Jaune Arc exits the restroom, Trivia Vanille will slap Emerald Sustrai on the ass. Emerald will get embarrassed, but not too angry, and Trivia will not question why she did this." That should do as a small test there... He noted that the ink didn't glow red and fade this time, so he took that as a positive sign, but he remembered that feature was a stylistic choice on Ria's part, that she could have changed at any time just to mess with him. So, he'd have to see if it actually worked to be absolutely certain.

He walked out, almost holding his breath in anticipation. Both Emerald and Neo looked up at him, before the latter grinned mischievously, and proceeded to slap Emerald right on her shapely rear. Emerald yelped and jumped up, going red, before turning on Neo. "What was THAT for?" she whined.

Neo just shrugged, before cheekily sticking out her tongue at Emerald as Jaune sighed in relief. Okay, first test done. Now he just needed to see if the partial immunity was in place.