The Shower Effect

When one mistakenly thinks that one is alone in the house/apartment, and begins to do things one wouldn't do it one was with other people -- like singing, laughing at pictures of Hannah Montana, or fapping.

While urinating into a lavatory, the main stream is entering as normal, but a shower like spray diverts and causes particulates of urine to land on the toilet seat. This is usually followed by a rapid wiping of the seat with toilet roll, often masked by the flushing of the toilet itself.

When you fart in the shower and the water intensifies the smell.