5 Stars for a helpful answer-if you have a dog and a cat or know a lot about either one please answer!?

First, you need to take the legal steps to ensure that your cat stays yours. In a situation like this, your roommate can claim that the kitten is theirs, and the older cat is yours. You should get the kitten microchipped and put in your name, that way nobody can claim the kitten as theirs when your name it literally under their skin.

Then tell your roommate that you really do appreciate helping the kitten feel welcome, but you think that their cat is upset about it, and that they need attention from you, not the kitten. If they don't get it, try to keep the kitten in your room as much as possible.