The Fist and the Devil

At 4'10" and 100 and some pounds... :-) I'm not the strongest person, but I have a pretty good grip. My son who is a bit taller than me and was just getting into working out was getting pretty strong. He was pretty strong, actually. I instructed him, "Hold out your hand, now clench your fist as tight as you can." So he did, to the point where you could see the blood start to pool under his skin by his index finger and thumb. I asked him to try to stop me from poking my petite finger into his fist. I tried just between each finger at first, and he smirked because I was unsuccessful. I then tried by his index finger and thumb - again no success, and his smirk grew to a grin. He felt satisfied that there was no way he was letting me poke through his fist. He was too strong.