Sheflex
Any reflex that girls have (much more common with spazzes), in which they let out a high-pitched scream, jump back unnecessarily, hit someone/something, etc. In all cases, it is just an overreaction to something simple.
"Hey, did you see me scare Brittany over there?"
"Yea, but her sheflexes reacted, and she kicked you in the balls."
"Yea, but her sheflexes reacted, and she kicked you in the balls."