Johnny sent me a Wikipedia link on Dog Communication and asked me to read the section on 'Licking'. I read it outloud and my heart immediately melted because it describes what Palmer does to Johnny and me all the time...now we finally know what he's been trying to tell us! Read for yourself:
Dogs like to lick human skin not only for the salt from the sweat, but also as a form of greeting, such as by briefly licking a person's hand after sniffing it. Licking is also used as a social bonding analogous to primate social grooming and stroking. This can indicate intimacy. Such licking is longer and slower, as compared to the brief licking of faces during a greeting.