Explains his situation to him.

"Alright, you can talk again, but calmly," Ria nodded.

"...what exactly is going on here?" Ren asked.

"I'm so glad you asked that," Ria remarked. "I'll tell you everything, but no getting upset at me or at what I say, okay? I'm not actually human, I'm a Sex Goddess, or an Erokami. You see, I dropped a copy of one of my tools, the Sex Note, upon this World, and your classmate, Jaune, happened to pick it up. It basically causes sexual scenarios by writing them in it."

"...so Jaune has been using it to manipulate the women of our class?" Ren blinked.

"Eh, manipulate is a bit of an ugly term, it's more like simply skipping over the seduction part. Besides, the girls are a lot happier like this than when they had sexual inhibitions, well, other than Weiss at the moment, but I can tell she'll come around soon enough. The Note is a wonderful thing to get rid of those foolish notions you humans have of being exclusive to one another, instead of seeing sex as a way to give each other pleasure. And it also removes the risks of STDs and pregnancy, so once those are out of the way, there's literally no good reason not to have sex with someone if you want to.

"All these societal prohibitions, and religious taboos against a natural and beautiful thing are something I just don't understand about you humans... Which is part of why I gave the Note to Jaune. Despite him having good morals to protect the innocent, at the risk of his own life, and desire to be a hero, he was in touch with his lust. Thus, he used the Note, and is not only having fun with it, but making sure all parties involved are as well. As I said, all the girls are happier than they were before. Other than what he's doing to Weiss, I fully approve of his actions, and even Weiss is not crossing a line in my eyes, she is a bit of a stuck up bitch, but she'll come around and enjoy it eventually too, so that's easy enough to let slide, so long as he doesn't make a habit of that."

"...I see..." Ren said, finding he wasn't at all upset about this, just as Ria told him not to be. "So where do I fit in?"

"Well... Jaune apparently saw fit to thank me for giving him such a gift, so has made you my plaything, within some limits," she smiled, grabbing his hands and putting them on her chest. "Play with my tits."

Ren obliged, blushing lightly. "Within a few rules, such as not getting you in trouble," she cooed as he squeezed her bust. "You're compelled to obey me... But don't fret... I'm not at all stingy when it comes to sexual pleasure, nor will I interfere with your life. And you'll find the experience quite... Divine."