Lost in his panty-fetish fantasy, he strokes his cock with increasing urgency. The friction of the fabric against his pulsating shaft sends shivers down his spine. He imagines the panties' former owner, their scent and touch fueling his desire. His breath hitches as he feels his orgasm building. He lets out a low moan, his body tensing as he cums, the panties filling with his hot, sticky seed. He collapses back, panting, the evidence of his pleasure soaking into the fabric, a satisfied smile playing on his lips.