Kitten tried to bite me again - why?

My 6 month old male kitten and I were having a kip in the chair for about 2 hours. He slept alongside me and after a while he tends to stretch out and sleep alongside. He stretched out so much that his neck and head hung over the end of the chair and he would have fallen in his sleep if I hadn't of brought him back up. When I did reach for him and moved him back on the chair he moved his head round to bite me, but I quickly let him go. What went wrong? I love my kitten, but I hate it when he tries to bite.