the act of lodging all the fingertips, preferably knuckle deep, into an orifice simultaneously, and then spreading the fingers as wide as possible.
"I'm on my period. It feels like Edward Scissorhands is spike-and-spreading my vagina."
Guy 1 - "Dude, that girl was a total freak!"
Guy 2 - "No shit!"
Guy 1 - "Yeah man, she totally let me spike-and-spread her!"