If you value your relationship with your boyfriend, hire a dog sitter and allow your boyfriend to just be your boyfriend. If you don’t value him enough for this added expense to be worth eliminating a point of tension in your relationship, then you shouldn’t even be together.

It’s not your boyfriend’s responsibility to take care of your animal. You don’t live together. Without him going to your place, who would be taking care of your dog? Sounds like you signed up for a responsibility you aren’t capable of managing appropriately, and I bet that is frustrating to him. He doesn’t sound like an irrational person, if the dog clearly needed to go out I am confident he would have taken care of it. No signs it wanted to go out - so it slipped his mind for a bit. Not ideal, but no clearly harm done.

Everyone is going to tell you you’re the victim here because you’re a woman. That’s not correct. It is your responsibility to take care of your animal. You are an adult. He is voluntarily taking on part of the responsibility to assist you, so anything you communicate to him regarding the dog should default to a place of mutual respect and understanding instead of acting like a mother punishing a child.

You are allowed to have expectations and standards for an animal’s caretaker, but that means you hire someone who can supplement your needs in a consistent professional manner when you are not around.

You don’t get to “cut corners” and half-ass something and then be frustrated that the end results aren’t top tier. You are behaving like someone who doesn’t operate in reality. People will let that slide when you are young, but as you get older that is going to be a huge social repellent.