A term to that Tumblrinas, Feminists and Social Justice Warriors use to explain how offensive something is. Most commonly used in situations where they see something where a [Cisgender}, Heterosexual, White male exists.
White Male: *Exists*
imsofuckingtriggered on Tumblr: "You oppressive scum! Check your privilege! Your existence is triggering to women, LGBT and P.o.C! Kill yourself!"
When fingering a girl with your first two fingers in the vagina and thumb placed on the clit essentially with your hand in a gun position using your thumb to "pull the trigger"