Counting the Beat

Erik uses a metal sex toy (dildo, butt plug, nipple clamps, handcuffs, or maybe he just molds something) on Charles with his powers so he can watch from afar while fucking Charles senseless. Belts, buttons, and zippers are metal too, so I imagine Erik just sitting back in a chair smugly while he uses the metal on Charles' clothes/body to force Charles around and take his clothes off and such. Maybe there's a bit of power play going on where Charles tries to get in Erik's head and make him squirm and Erik disciplines him for it...