Is AUTHOR wrong in the post ? POST : So I am going to start off with some back story.

My husband and I are moving in with my parents this week in order to save money to buy a house. 
At the end of march my cousin is going on vacation for 9 days and asked if we would like to stay at his house and I would feed and water his dogs and take them on a walk occasionally in that time. But mostly it would just be so we could have a place alone for a week or so. He has another family friend that lives a few houses down from him that could easily take care of the dogs. They are outside dogs with the ability to go into a heated garage or dry chicken coop to stay out of the elements. They used to be inside dogs until he moved to this house and his yard is half mud so he doesnt want them on his new hardwood floors and carpets.

So here is where the question AITA comes in. I have a German Shepherd puppy who will be about 6 months at the time we go over there. She is attached to me at the hip as I do not work and she goes every where with me.
After initially asking my cousin says "you can bring your dog but she has to stay outside or in the heated garage but I dont want her in the house" 
I let him know that's not going to work. She needs constant supervision and she also isnt going to do well and probably back slide in her training if she is left to her own devises for 9 days.
So he follows it up with "well you can put her on a leash and just make sure she stays in the kitchen. I would pull the rug up in the living room but that's just a lot of hassle having to move the couches off of it"
So I politely declined saying "thanks for the offer but I'm sure only a month in to living with my parents we arent going to need a break from them and it will just be too much of a hassle for me with all of the rules my dog will have to follow. Since he already has someone near by to care for his dogs it's probably better for my sanity and my dogs sanity to just stay where we will be at"

Over the phone he was really cool about it but then at the bar last night he was going on about how he was just trying to do me a favor by giving me a place alone with my husband for over a week. Blah blah blah. But because I dont feel like respecting his rules and want my dog to just have "free reign" over his house. I'm not going to take that offer.

So AITA for declining? Because I feel like me staying there is more me doing him a favor by watching over his house and dogs FOR FREE at a place 50 minutes out from where I live? But he seems to think other wise?