We have a year and half old Boston Terrier/Poodle mix that we've had since he was 8 weeks old.
He's my daughter's dog and I'm very careful to make sure that she provides all his care (feeding, walking, sleeps in her room, etc.) however he seems to have decided that he belongs to me.
When I'm home he prefers to lie on my feet and will only go to her if she has a treat or I make him. When we try to do any training he will mind me and ignore her, he tries to sleep in my room every night in spite of the fact that he's NEVER (not even once) been allowed and will make her chase him before he will go with her.
He's a VERY smart dog. It literally only took me about three repetitions to teach him "sit" for the first time. It only took me once to teach him to sit for his leash. It took once or twice to teach him to fetch, etc.
But again, when she tries to get him to perform she has to repeat and repeat and sometimes even has to physically make him do what she tells him (e.g., push his behind down to make him sit, pull his front legs out from under him to make him lie down, etc.).
When we come home together he will greet me (overly enthusiastically) first and may or may not greet her at all. When she neglects to take him out in a timely manner he will pee/poo in my closet or on the floor in front of my closet if the door's closed.
I'm just trying to figure out how to make him more responsive to her. It's great that he loves me (and I've actually come to love him as well) but I didn't want a dog to begin with - this is HER dog.