My 8 week old kit Oscar is playful and when he play bites its fine he doesn't hurt. but yesterday he left gashes in my fingers after he was exploring, in my lap (I was looking at his brother Meeko as i was about to pull him away from the sofa) then Oscar got off my lap and made a weird noise and lunged at my finger and shook his head while continuing to hiss and make noises, it hurt a lot so I pulled away and it was quite deep, since then he has done it again twice and I can tell this isn't playing. I have tried scruffing, hissing, drag across the floor and sanctioning after he has done it but after all that he just bites me again, my fingers are very sore...any advise would be appreciated :)