When Catcher was a puppy he would do that... he would actually pull my skin while biting... OUCH! But if I turned away, quit playing, etc., he just didn't get it. He mainly did it while I was playing on the floor with him so I stopped doing that for a while. Now at 10 months he still will start to bite and I'll turn away and he "gets it". He will immediately stop. So, I think you may just have to try to get through it..... I would keep letting him know that biting isn't acceptable by stopping playing, etc. and eventually he'll understand what is going on.