Lets her lecture him... Naked.

"Hold on, let me at least finish my current paragraph on my assignment before I lose my train of thought!" he called out to her, grabbing the Note.

"Make it quick!" she huffed from the other side of the door.

Sylvain smirked and got to writing, "After Sylvain Gautier lets Ingrid Galatea into his room, she will close the door, and then strip naked. She will not notice, and subconsciously show off her body to Sylvain even while lecturing him. Once she is done, she will get dressed and leave, never noticing she stripped down and redressed in the first place."

He then got up and unlocked the door before opening it. "Come on in," he put on a fake sigh, as if not looking forward to this.

She stepped in, closing the door, working on her top immediately after. "What is your damage?" she demanded, undoing the last button on her coat and sliding it off.

"...well, I sparred with Dimitri yesterday, and I'm still feeling sore," Sylvain joked as Ingrid took off her undershirt, revealing a black bra.

"You know damn well what I am talking about!" she snapped as she unclipped her bra and dropped it, drawing Sylvain's attention to her swaying boobs. "Don't think you can weasel your way out of this with your dumb jokes!"

"Okay, sorry, just trying to lighten the mood," Sylvain said, raising his hands. "Sheesh!"

"You do realize I'm going to have to apologize to the Professor on your behalf, don't you!?" she demanded, even as she undid her skirt and pulled it down along with her panties, leaving just her shoes and socks.

"Hey, don't worry, I already apologized," Sylvain protested as she stepped out of her panties and lifted a leg to pull the sock off, along with the shoe.

"Oh really?" she scoffed, doing the same with the other foot. "Was it an actual apology, or was it something along the lines of, "I'm sorry you think my behavior is a problem?"" Now naked, she stood with her hands on her hips, completely unaware that she had stripped.