My kitten licks me then bites me really hard why?

I bottle fed this kitten, very playful lovable, but sometime it will start to lick my face then it just chomps right down on whatever its licking really hard like he is trying to eat me..the other night he did this to my fiance he was on his shoulder licked his ear onced then clenched onto him and would not let go we had to pry his mouth open..why does my kitten do this..?