Mouth licking in dogs is typically associated with hunger or uncertainty and while it can precede aggressive behavior, I doubt that is what you are seeing. read more
This is a way dogs tell each other they are not looking for a fight. Other calming signals are yawning, looking away and when they put their paw on top of your arm when you pet them. You can surprise your dog by speaking their language. When he licks his lips, yawn, look away and lick your lips. read more
My dog licks his lips a lot of the time when I pet him, and I've read that this is a stress signal, but he doesn't seem stressed at all. He'll come up to me and put his head on me for me to pet him or it will be when laying in bed (he sleeps in the bed with me). So, it seems strange to me that he would be stressed when he seems so calm. read more