After completing the act of simple, everyday bukkake, the dudes chuck a handful of shaved pubic hair at the girl's face whereby it sticks to the semen residue turning her into a hairy beast. If she doesn't suspect the addition of pubic hair with her dose of cum, she may object vehemently. With a throat full of semen, the angry gurgling sounds like a Wookie. While this last part isn't necessary for a Bukkake Wookie, it's a nice bonus.