The act of someone, in most cases female, seeking to see if a man is lying or already in a relationship by asking several questions of the CSI-ee and friends, looking around the apartment/house and/or online for clues like a Crime Scene Investigator.
Leah noticed a bra in a man's bathroom, dishware for two, and a photo collage of a girl in the guy's place where she has visited for the first time.
"The second she entered the house, she began CSI'ing the place."
"The second she entered the house, she began CSI'ing the place."
by BluePumpkin May 20, 2009
after watching too many episodes of C.S.I., you start thinking that you are a "CSI" when things go weird thus you investigate or start "CSI'ING" what you don't now or understand.
man, my lighter is missing, I know one of y'all took it, 'm gonna be CSI'ING the shit outa this place till I find it yo!
by kagic February 06, 2016