The best way to prevent it becoming an issue is to work on it now! Show him that you're never a threat to him or his things. I do that by sitting with my puppy while she enjoys a bone, or food, or anything else of high value. I don't ever take it from her, but I can if need be, because I handle things that way generally. Matter of factly, not whimsically. That being said, you need to taylor your response or actions to your dog. Judge for yourself how far you can go, press those limits, and praise and treat wildly when those boundaries are stretched! It's a learned behavior, so teach it!
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain