At first it felt like he could stay here forever, now he's racing headlong for the finish- body curling up tight to hold more of David as he twists and thrusts, breath coming in great shuddering gasps as he tries to hang on long enough to get David off. When in doubt, and stimuli- he sneaks his free hand down to curl around David's cock and give it a squeeze, hand working slick and hard over the sensitive skin.