My Secret Love for My Niece's Dog

I've been watching my niece’s dog, Buddy, grow up over the years. He started as a tiny bundle of energy, and now he's a big, lovable Labrador who knows how to command attention with just one wag of his tail. I dote on him like it's nobody's business. I take him for walks when she's too busy, give him extra treats (her rules be damned), and secretly keep track of the dog food supply to ensure he doesn't go without even a single meal. It’s gotten so bad that if you walked into my house unannounced, you'd find Buddy napping on my bed or curled up in one of his favorite spots around the house. Now, here's where it gets tricky. I’m not just his caretaker; I’m also kind of possessive about him. If someone suggests to me that my niece might move with Buddy to another city, I feel like a part of my heart breaks. It’s absurd because he’s her dog and she’d be the one making such a decision, but I have this irrational belief that I should be able to dictate where he ends up living. I mean, can you blame me? He's the best thing in my life these days. Anyway, as much as I love Buddy, it recently came out that my niece is considering adopting another dog. The thought of having two dogs around is making me feel a mix of excitement and dread. I'm torn because while adding another furry member to our family might mean more cuddles for everyone involved, it could also mean less attention for my beloved Buddy. So here's the big question: Am I being an asshole by feeling this way? Or do others understand that sometimes you just form such strong bonds with a pet that they become an integral part of your life? Let me know in the comments if any of y’all feel similarly or think differently.