Write a condition in the notebook.

"Well," you say opening up the noteboook. "Let me consult my spell book."

Sadie chuckles.

You have a perfect excuse to touch the notebook at first. You make a show of reading it, tracing your fingers across the lines where you've made changes. But once things start going you're not going to really be able to write something on the fly.

"So did you have a size in mind? In my vast experience with magic, things work best if it's closely rooted to your preferences." Well at least in terms of her getting into the sex. "How about you tell me what you want, and I'll figure out what spell I need to use."

"Seems logical." She drums a finger on her cheek. "No reason to go super crazy I guess. How about Triple Ds?"

How you react to this might make a difference on how well she receives how you move forward.