I don't think you are ridiculous, just a mom who's relationship changed with her kid (furry or not
) anyways, not an expert as to why that happened, but I think the new pup is just that.. new.. and he likes her. She may be able to play in ways that you couldn't. I dont' think that means he doesn't "like" you anymore just that he has a new friend. Just like when we get new friends we tend to hang out with them a lot more too. Not to mention his routine has probably changed with him so he's adjusting.
Also, just curious.. do you let him pick where he sleeps? I don't give Titan that option.. he's in my room no matter what. Maybe you just bring him up there regardless if you want him in your room.