IIN to find guy's underwear a turn on

When my cousin was staying with us recently he took out gym membership and I loved his smell when he came back from his workout. He always showered back at home and I longed to get in the shower with him but never did. His scent was arousing and he would wear his underwear for a few days and leave it on the floor in his room. No skid marks fortunately but a wonderful smell of light piss, sweat and sweet musk. Also the usual cum stains. Would masturbate to this whenever possible