"Take off my shirt and lie down?" Lizzy is clearly worried you are up to something. You are of course, so best to sound as professionally disinterested as possible.
"Yes. Your clothing absorbs some of the soothing I am providing, so the direct contact improves the experience. Lying down, you give me a better angle to apply pressure to those stubborn spots."
All very true of course, but of course more important in your view is that either takes her a step closer to a tasty fate. But Lizzy doesn't know that, yet...

"Well, I guess..."