This really hits home for me (35F) - My fiance and I would both be just as pissed as you are if the other brought home so much as a fish without discussing it first. And this is why....

12 years and a lifetime ago, ex boyfriend of approx a year decided to bring home 2 shelter kitties. This was HIS house, so not my call. Soon after I move in with him and his cats. I grow very close to one of the cats. He's a mouthy Tuxedo that I just love to pieces. The other is a calico and our relationship is pretty much that we tolerate each other, but I love and care for her just the same.

2-3 years later bf and I break up, and I tell him I am taking my little boy with me. He's fine with it but doesn't want to split the two up, so you guessed it, I take both cats.

Fast forward a couple of years, I am in a new relationship and our life is hindered by the responsibility of these cats. We have to consider their needs with apartment selection, travel plans, etc. We are looking to purchase a house soon and I am only considering houses with some enclosed outdoor space so the damn cat can go outside because he loves it so much and has been stuck in apts for a few years. New bf, now fiance, accepts this, but we both know that the root reason we have this responsibility because of a choice my ex made. Granted, I chose to take them at the end of the relationship, but I would have never gotten the cats myself.

The calico just passed away 2 months ago. Seeing her weak and in pain and ultimately having to put her to sleep was beyond heartbreaking for both of us. Tuxy misses her, he's kinda lonely and has been needier than he already was, and trust me, he's a handful.

We've talked about getting him a friend, but decided that we do not want to take on another 20-year long responsibility right now, maybe later when we buy the house.

Point being, I feel your pain on this. I am curious why she did this. Did a friend have a cat that needed a home, or did she go out of her way to get this cat?