He was very well socialized as a puppy. I am home with him all of the time. He actually goes to a kennel when I have to leave town and does wonderful there! Loves other dogs. You will find this interesting though....once when I picked him up from the kennel the husband was there when I arrived. The wife volunteers at the local shelter and was gone. Hershey was there with the husband doing fine. When I walked in the room to get him Hershey ran to my side sat to the side of me looked at the man barked and growled at him and acted like he does at home when someone new arrives!! The man was shocked! He said Hersh and him were having a fine time before I came. So....it is obviously ME! I'm just not sure what I am doing wrong.
You need to take control. I too have a business in the home, but have 6 (actually 7 w/ the baby) labs, not just 1. When I expect folks, I try to have my dogs in their crates in the attached garage otherwise it's an overly friendly thing... but really the same principal, the dogs are like kids-- not to be in charge. I am. My house, my work!
That all said, I'd get him back in obed classes and make sure he understands who is in control. He seems quite confused. Good luck.