My 2 1/2 yo rescue boy did that. He was a biter, a nipper when I got him. I would tell him "no biting". He would jump in my lap then in my face and lightly nip my lips, each time I told him no biting. It took several weeks to stop that lips nipping.
__________________ Joan, mom to Cody  RIP Matese  Schnae  Kajon Kia  forever in my  A House Is Not A Home Without A Dog |