n'aww! grabs ferociously and then licks it better! that's what my cat does to my hand...its' like he can't bring himself to bite me...it's so cute...except when he actually DOES bite me...that's not fun...
I love seeing big siblings play with little siblings. My Grandma's kitten Arthur is particularly fond of rough housing with his baby brother Nelson. I wish I had been there to see this, but one day my Grandma was calling Nelson to her. He usually comes when he's called, but she was calling for quite sometime without him responding. All of a sudden Arthur comes over to her carrying Nelson in his mouth.(like a mama cat would)
That bigger cat was either playing with that kitten or the kitten did something that wasn't alright to to the cat and was telling the kitten to stop. Older cats usually will do that to the kittens, it's their way of a mom scolding their child.
Big kittens play with little kittens all the time when they're around. They area actually very gentle with their little siblings. If things do get rough, mama usually comes and breaks things up. Two of my grandma's kittens, Penny(big sis) and Arthur(lil bro) were playing one day. Lil' bro was trying to stuff big sis under the china cabinet.