New er spaniel- loves my girlfriend but could care less about me.?

My girlfriend and I just got a 16 week old male er spaniel on Saturday. He instantly fell in love with Tracy and only gives me attention when Tracy is right there with me. Yesterday Tracy put Bo in the crate when she went for work at 1:30. I got home at 4 and opened his crate and tried to get him to come out. He refused and actually growled and snapped at me when I tried petting him. He came out after an hour and half only to go to the door because he had to go to the bathroom. Even when I tried petting him and praising him for going to the bathroom outside, he didn't want anything to do with me..almost left the treat outside so he could go back in his crate. It wasn't until around 7 that he would actually come out and let me pet him and play with him. When she came home at 10, I was basically invisible. WHat can we do about this? It sucks that I can't really play with him and it's not fair to Tracy-she has to take him out every hour at night and Bo won't go in the morning with me.