All over her ass.

You pull out and stroke yourself to completion, shooting forth ropes of pearly white seed across that perfect ass, striking the underside of her raised white uniform skirt, and she moans at the feel of it. It keeps coming and coming, running down between her cheeks, down her legs, dripping from her garters and down onto her stockings, covering her ass in your essence. The nurse reaches back, rubbing it into her skin, shivering in delight, and brings her fingers up to her mouth to suck them clean.

"Niiiice," the nurse says, rubbing it into her skin, making those round, full cheeks shiny with your cum, and collecting the drops from her stockings and garters, licking them off her fingers while those blue eyes watch you. "Mmm..." she says, savoring the taste of it.

She stands up and smooths down her uniform, then nods her head back the way you came and leads you back to the lobby. There she gives you your pay for "donation" and her phone number--all in all, a very successful venture.