A masterbation technique in which the user takes a shower while masterbating. At the exact point of climax the user simultaneously switches the water to ice cold. Creates an extremely relaxing effect.
I preformed internal combustion in the shower and I feel so relaxed!
by Solcomets September 30, 2010
Its an engine you moron
"Thats an internal Combustion Engine"
by Nelsy fellow February 20, 2021