Bailey,
What a handsome guy you are!! Two great breeds together with a Lab/Boxer mix so he's got to be a fantastic fella. Sounds like he's readying himself for the addition of a new little one. You are so wise to get him accustomed to the changes in a gradual way. He'll be an awesome babysitter and will most lilkely let you know if something is awry. What a combo you've got there. Congrats!!
Donna