Viper, a dog trainer isn't a bad idea. Both me and my mother go to a dogschool. There we learn how to train our dogs in an efficient way and at the same time, the dogs interact with eachother and other people. One of the exercises we have to do is let someone else take the leash of our dog and let them walk a short distance. If the dog starts to growl or something similar, we have to punish it.
This way the dog learns that it has to allow other people to touch it and give it commands. It also reduces their hostility towards strangers.
Ofcourse if your dog's just playing, and doesn't mean any harm, it's a tottaly different matter. Our dogs like to jump against people when they're happy, and we aren' able to unlearn this behavior. It can be pretty annoying, I got a 5 year old cousin, and when the dogs see him, they just jump at him, causing him to fall.
Still, don't discard dog training as a solution, if you don't have the time to train him, maybe your wife/girlfriend has. It would make your life a whole lot easier.

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