I think you little guy will come out of his shell sooner than later. I just bought a little girl that was 7 months old and I was so worried that something was wrong with her because she just would not do anything but sit next to me on the couch too. This is all going on while my other little boy who is a month older than her is bouncing off the walls. I have had her about 7 weeks now and I must say she is one playful little girl. Not as much as my boy but she has finally come out of her shell. She LOVES to chase toys and my little boy yorkie around the house. So I think it will just take time and you will see. You have to remember when you get a Yorkie like we both did - they have been used to a certain life style already so it takes them some time to adapt to the new life style you are giving them. Who knows I am sure my little Mia was thinking - where am I?