They fail to notice

Jess absentmindedly grabbed her milkshake and continued to argue with Tiffany about her use of wishes, "You need to warn me before you make wishes so that I can brace myself! Otherwise it just comes out of nowhere. Imagine if I am in class and you decide that it would be fun to wish for something! You might be able to prepare yourself, but I can't and might make a scene! Seriously Mistress, show some restraint!"

Tiffany was rapidly drinking her milkshake, finding it delicious. Looking up from the drink, she sees Jess drinking with the same intent she was, while Ernest sipped his tea, appearing extremely relaxed. Taking another suck of the milkshake, Tiffany did her best to come up with a solution, but kept getting distracted by the milkshake. She stopped drinking, and soon came up with an idea, which she immediately blurted out.

"How about... I wish that Jessica becomes aware when I decide to make a wish so that she can prepare herself. No, wait, I didn't..."

Tiffany was cut off by her own moan as as wave of pleasure rushed through her. Jess, sitting across from her, felt the same rush and orgasmed on the spot. Ernest looked on with a confused look on his face, then realized what had happened and blurted off some excuse to leave before things got too heated between the girls.

Jess began to shout irately, "SERIOUSLY!?!? At you even listening to a word I've been saying? Stop using the ring so much, especially if you aren't going to warn me first! It's infuriating!"

"Come on! It was one harmless mistake, I didn't mean to make that wish without telling you! It's just some fun, no need to mother hen my usage of the ring!"

"Usage of the ring? Mother henning? This is my life you're playing with! Your 'fun' is just you taking advantage of my kindness. I'M the one who decided to give you the ring, but now I think it would have been safer in Ernest's hands!"

"Fine. I wish that Ernest was here."

With that, Ernest, who had run to the boys bathroom to wash his face and try to fix the mess that was coming, appeared in his seat, confused at Jess and Tiff, who were standing up glaring at each other. Tiffany slid off the ring and handed it to him, saying, "Here. Jess thinks the ring would be safer with you, and I don't want to deal with her attitude anyway."

Ernest put on the ring, and suddenly both girls felt light-headed and dizzy. Sitting down quickly, they felt all their anger drain away. They stare at each other, confused as to what just happened. Then, their actions hit home, and the look over to Ernest, who has slid the ring into his finger and is prepared to get wishing.