>be 14
>watching porn and jacking off
>window closed, door closed
>jack off for a good 30 minutes before going outside
>ejaculate into the toilet (didn't like using paper towels and ejaculating in my room in general)
>flush
>"Anon!" my mom calls
>"what?" I see her in my room sniffing the air, looks at me
>"are you masturbating?"

This traumatic event has always eluded me, because the room did not smell of ejaculate, and I didn't ejaculate in the room. But she swore that she could smell that I had been masturbating. I've done a few experiments since then, and it's true that the room usually smells like sweat, but different. What is the /sci/entific explanation for this? Pheromones?!