Ask some questions

You let Amelie into the room and she takes it as a 'Yes' but you gesture for her to sit on the bed while you sit on a nearby chair.

"I have some questions."

"Yes?"

"First, are you married?"

"No. Or do you prefer if I'm married?"

You do, actually. Paradoxically, it makes easier for you to decide what to do. You can reject her using that as a pretext, or, you can do it with the knowledge that she is most likely to keep it a secret, at long as Jan is not involved. Thinking about it clearly, a bit challenging since you are distracted by the woman in front of you, Jan is not telling the wench to fuck with you simply because he wants to know whether you're good. Amelie doesn't lie, of course, but she only repeat what is told to her.