The act of masturbating while taking a shower. The wetness and steaminess makes it feel amazing, yet it usually takes a little longer to have an orgasm. It is also very efficient in terms of cleaning yourself off afterwards.
Ron: "Bro, I just shasturbated while thinking about Emma Watson!"
Daniel: "Nice, dude, that must have felt awesome! Shasturbation is the best!"
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.