The experiment

Henessy shows up first, dark hair pinned back, lab coat buttoned wrong. Marcus is already mixing something at the bench. She steps behind him, slides her hand over his zipper while he keeps stirring. The glass rod clinks against the beaker when she lowers to her knees. He turns, lets her free him, and she takes him into her mouth without ceremony, tongue working slow then faster. His breath catches; he braces one hand on the stainless counter. She rises, bends over the same bench. The coat rides up. He steps in close, pushes in with one steady thrust. Her knuckles go white around the metal edge. They move hard, the slap of skin sharp against all that chrome and tile. Marcus pulls out at the last second, finishes across her face, streaks hitting her cheek and lower lip. She stays bent over a moment longer, catching her breath, eyes half-closed under the mess.