You have a golden, they've been bred to want something in their mouth - if you don't offer them something, your arm or pantleg will do!
Get lots of stuffies for him for when he's around the house loose - don't leave them in the crate as they can destroy and eat them, not good!
Have the stuffies handy and when he comes to say 'hi' hand him a stuffy and then praise him up. Don't take it away, you can trade him for a treat and hand it back, but do lots of 'oh what a nice toy, what a good puppy!' with him. If he drops the toy and goes for your hand, stand up and walk away. He's invisible without the toy (or at least pretend he is). Soon he'll go grab a stuffy himself and bring it to you for attention.