Truth
“Ahem, no, i do not take photos, i just load a new filmrole into the camera and thats making strange noise.” What a bold lie. And she will detect it. Digital cameras do not use film anymore :) It sound fun, it may be fun but normaly it is not so so good to lie to your model. It will end your emotional layer in a second.
Tell her what you do next. Say the truth, no lie! Girls like it to look sensational, so tell her if she is. Let her feel your enthusiasm. “What a wonderful bra, boah, keep this position a second”, klick, klick, klick. “Wonderful lingerie you own, it fits so beautiful, looks so good”, klick, klick, klick, “And the sunlight on your body, stunning, turn a bit to your left, Thanx, that is WOW”, klick, klick, klick. Each Klick one photo. Giving her positive response motivates her to move as you wished. Let her feel good, acvtivated her potential. And you got what you wanted. And she got what she wanted ! Again a WIN-WIN situation and hopefully good pictures with an impact ! Try it and enjoy.
Details: Olympus E-5, Zuiko 12-60SWD, ISO800, f3.8, 1/80 second, 42 mm focal length. No additional light used, no reflector, just the sun thru the window.