My wife and I adopted a rescue dog a little over 2 weeks ago. We don't have any background on him, just some vet records from the rescue, and they believe he is between 1-2 years old. My wife is a little upset at the moment that he "picked me as the favorite" over her. Her basis for the claim stems from a few daily examples. We have a small workout space in our basement, big enough for one, so we take turns working out in the morning while the other is upstairs. When I am downstairs he sits/lays at the basement door and cries/wines. He does not do this when my wife is downstairs. When I shower or use the bathroom he will wait outside the door until I come out. He also does not do this for my wife. I don't want this behavior to get worse and turn into separation anxiety if I am not around.
So do dogs actually have a "favorite" or could this be the start of separation anxiety? And how could we go about correcting this behavior?