The rather difficult task of masturbating with the left hand while using the right hand on a mouse to navigate porn on the Internet.
With practice you can become ambidextrous; however that in no way discriminates against ambidextrous men who are born that way.
When my mother goes to the supermarket I have a quick left hander.
Someone who smokes cannabis; a stoner. A normal cigarette is called a "right-handed cigarette" and a joint is called a "left-handed cigarette". This is a special code used to allow people to speak freely in public about their plans to smoke pot.