Very few

"I am having very few terms in mind, Professor." Petra says, before pausing. "Though I am having a thought on the topic."

"Such as~?" Sothis cooed, looking at her with intrigued eyes.

"I would like to keep things interesting when it comes to the art of sex making." She explains with a nod. "Beyond that, just what I assume to be regular rules, like the option to say no when I choose. Other than that, nothing arrives at my mind."

"It's 'nothing comes to mind', Petra." Manuela corrects her. "And that sounds like lovely conditions to me. What do you think, Master Byleth?" She asks while Dorothea nods along with her seniors sentiment.

"Sounds perfectly all right to me. Sothis, I wish she was a member of the harem with those standards." The possibly divine genie snapped her fingers as she floated over to grope Petra. "Oh you're going to be so much fun, I know it~! What do you want to try first~?"