Hey Rachel!
I totally get where you’re coming from. Charlie went through a similar phase when he was a puppy, especially when he was excited. It’s totally normal for some dogs to use their mouths when they’re happy or playing. But I agree, you definitely don’t want that behavior to get out of hand, especially around kids or guests.
What worked for us was redirecting the nipping behavior. Every time Charlie would start nipping, I’d calmly say "no" or "ouch" in a firm voice, and then immediately give him a chew toy or something appropriate to bite instead. Consistency is key here if you keep offering a good alternative, he’ll learn that mouthing toys is okay, but mouthing people isn’t.
It might take a bit of time, but with consistent redirection and positive reinforcement when he does the right thing, Ollie should get the hang of it. Just be patient and keep the training consistent!
Good luck!