I sub-let a room in my home to a close friend. She has lived here for two months and wants a kitten. I said no for a number of reasons, but she argued and seemed mad at me.
I feel like I'm being unfair because my fiancé and I have a dog and a cat already. My friend works, studies and is very socially active. I know that I would have to care for a kitten and I don't think my cat would be OK with another cat as he is very territorial. She thinks I am being hypocritical. Am I being a bad friend? What's the best way to say no without causing a fight? When I said about her work/study/life she just said "i'll be home more". I don't know how to get through to her wuthout upsetting her.

I know it's a hard line but if you want to stick to rules, by maintaining a double standard, then your friend is sub letting from you, so if she can't follow your rules, then she finds another place to have a cat.

Otherwise let her have a kitten but it has to stay within her own domain and not out in yours. That means she will have to have a litter box in her room and take care of it herself. Maybe she won't find it so attractive if she knows she will have to clean and maintain a litter box, or any little mistakes the kitten may make along the way, like peeing on her bed, etc. Then of course if she gets a female, she will have to have it spayed, or a male neutered, and you know males spray.

There is some fuel for you.

It's your home, you gave her good reasons, (and tickle gave more), so tell her you are very sorry if she chooses to move out, but that's that. It's no different from you telling her that she can't knock out a wall - it isn't her house.

The fact that you have a cat and dog is irrelevant. It's your house, your rules. If it was me, I would also be worried about having to take care of her cat and then what if her cat decides to start using parts of the house instead of the litter box? That then becomes your problem.

A few more reasons against -- kittens have very sharp claws and will climb curtains/drapes and leave holes and tears in them. A lone kitten will cry a lot, especially if it is shut up in a room by itself and hears people and other animals on the other side of the door. One of our young cats even shredded the carpet at the bottom edge of several doors when it couldn't get into another room. Another young cat used a section of wallpaper on one wall and the arm of one chair as its scratching post. Kittens aren't bad but need a lot of overseeing and training, plus need an owner who is able to out-think what they will do next and be there to rescue them from bad behavior (and substitute positive opportunities).