You know what the dog may believe?
To discover whether you may be permissive rather than someone who gives permission to the dog to do X, Y or Z, try this Silent Movie experiment:
Videotape yourself training or just walking with your dog. Show this to a friend. Ask them what they believe you are working on in that video. Ask them what the rules you have for your dog's behavior based on that video. You may be surprised!
Like silent movie audiences, dogs must guess from the action, not the words, what's happening and what is intended. Sometimes, handlers make very confusing movies!
When permission is implicit - meaning it's not actually stated - the dog understandably can become confused. Worse, the dog can end up thinking he can do what he likes without needing to check with you.
Explicit permission involves deliberate signals that the dog can hear, feel, see. This may be verbal cues, visual cues, even touch cues. This may also be your entire body language and actions. For example, when I say "Go say hi" I often drop my head briefly, extend an arm or hand towards the person/animal to be greeted, and step towards them myself along with my dog. This makes my message "go say hi" crystal clear to the dog. And it is very different from the full body message of "no, sorry, not now" that I may give in another situation.
When you give explicit permission, you gain a great deal:
The take away message for your dog is that if I can "Go say hi!" at times, I can also say "not now" at others. This allows the dog to understand clearly that there are times when behavior X is fine but times when it is not.
"Permission, Not Permissive" by Suzanne Clothier