Looking waaaay back...Cody did the same thing esp; when he wanted HIS way. I had little scars on my arms to prove it!!! Of course Carrie is right (what else?) With the help of a wonderful trainer, who used Carrie's technique, I got right to the problem because it was getting unbearable, uncomfortable, nasty and frightening! And as I said before, I knew NOTHING being a first time dog owner so I was very very consistent with eliminating this problem. I finally took control! Cody is by no means perfect after 9 yrs but he does NOT jump (constant reinforcement) DARE to mouth me in any way. This had to be one of the worse problems I had to deal with!!!! Good luck! It takes time and patience!!!