Why do dogs lick? Well it’s all to do with pecking order. If one wolf became separated from the pack and (then) came back into the pack, it would immediately go up to the leader of the pack and lick the inside the lip, so actually licking the gum - that’s the first thing. Second, it would lick the ears. Thirdly, it would roll over and expose its belly. This is a normal dog behaviour, as per the wolf.
Some dogs will lick you, don’t worry about it, it’s a term of affection. Dogs that do a lot of licking, licking you - particularly they love to lick your feet or lick your face, just as they would do if it was another dog. I find that to be normal behaviour.
"Some dogs will lick you, don’t worry about it, it’s a term of affection.”
Dr Harry Cooper
Dogs that lick a lot are generally very subservient dogs. These are dogs that are very highly unlikely to bite you. And sometimes they’re a little bit anxious too. Don’t get overwhelmed, just tell them no. And one little trick that works better than everything else... perfume. Dogs and cats don’t like perfume. It's not the smell, it’s the alcohol it's dissolved in, they don’t like that.