AITA for getting upset with my girlfriend for feeding my dog cheese after I asked her not to?

I (M32) have a dog, who I’ve had for nearly 8 years. He has a sensitive stomach, so I keep him on a strict diet. My girlfriend (F30) of 4 years knows this, but last night she wanted to give him some cheese. I don’t usually feed him cheese, and while I know a small amount probably wouldn’t hurt, I didn’t want to give him too much at once.

Throughout the night, we gave him a couple of small pieces, but at the end of the night, there was some cheese left over, and she wanted to give him the rest. I explicitly asked her not to. She ignored me and walked toward him. I asked her again, and she threw one piece to him anyway. I walked over to her, repeated my request, and she tossed the rest of the cheese on the ground towards him.

I told her that was messed up and sat back on the couch, clearly upset. She eventually apologized, saying she didn’t realize it was a big deal. I told her I wasn’t ready to accept her apology yet because I was still upset.

Later, I went back to her and explained that it wasn’t really about the cheese—I was upset because she blatantly ignored my requests and disrespected what I said about my dog’s care. Her response was that “it was just cheese” and that I was overreacting.

So, AITA for being upset about this and not immediately accepting her apology?

— I feel like it’s less about the cheese itself and more about the principle of disregarding something that’s important to me. Am I overthinking this?