He probably isn't a fan of dogs. My SO isn't either... However, when I had my puppy (RIP) and he was over for an extended period of time (long distance), he was friendly with her, would go with us on walks, and actually played with her (shocking to me since I've never seen him friendly with a dog before). I know for a fact if we had lived together when she was still alive, he would have taken her out to potty if I wasn't home. He may not take responsibility of feeding her or walking her (not his dog, I would never expect that) but he does have a heart and would never force a dog to piss and shit in the home. It's not hard to just take them out and bring them back in. It's very cruel to not allow a dog out to potty. Your SO said he liked the dog and they were bonding... He lied to you. For me, that would be a deal breaker. If he had been up front and told you he wasn't fond of him and didn't want any responsibility, then you could have decided to stay with him and find a dog walker, or leave him. Instead, he lied and now you live with a man who abuses your dog (yes, not allowing him to potty and then being mad about him going inside is definitely abuse). Talk to your SO and maybe decide then if you want to get a walker and accept he lied to you and abused your dog or leave him.