It's quite fun, obviously!

"Alright, let's do this..." Ren nodded, and prepared himself for quiz ahead.

"Okay then~!" Ruby chimed as they studied Professor Port's material first. They gave themselves fifteen minutes to prep. "Okay, Ren, you ready for your first question?" Ruby asked him.

"Lay it on me," Ren nodded, and Ruby decided to give him an easy one first.

"Of these four Grimm types, which one are you most likely to run into more than one of at a time?" Ruby asked. "A, Boarbatusks, B, Ursas, C, Beowolfs, or D, Deathstalkers?"

Ren didn't even have to consider it. "That woud be C, Beowolfs. They hunt in packs."

"Correct!" Ruby grinned. "Now for your prize!" She got up on all fours, and turned her backside towards Ren, and gave it a wiggle. He blushed as he took a moment to stare at it. "You like?" she teased him.

"...yeah..." he admitted with a blush. He then turned to Yang to ask her a Grimm related question. "Where do Grimm come from?" he asked her.

"That's something that no one knows," Yang replied. "Studies on their biology, for lack of a better term, prove that they don't reproduce the same way as we and other animals do. There are theories that they manifest from negative emotions, instead of just being attracted to them. Others think they are spawned somewhere on Remnant, but no one has been able to find such a place. Ultimately, nothing has been proven."

"Correct," Ren nodded, before blushing. "Um... I'm not sure what to reward you with..."

"How about you just let me lick your cock?" Yang offered with a grin. Ren's blush deepened.

"That seems more like a prize for me, but go ahead," he decided, altering his posture to sit with his erection on display. Yang grinned as she crawled over, and licked his shaft from base to tip, taking it tantalizingly slow as she slowly drew her tongue up his length. "Unh..." he moaned as Ruby watched with a grin.