advice for introducing my cat to my boyfriends' two cats when we move into our new...

apartment together.
all three cats are the same age.
he has two brothers. i have a girl.
i'm really nervous about introducing them.
any advice??

I'll move this to behavior for you.

Simply follow the instrucions on this page to the best of your ability:

http://www.thecatsite.com/forums/showthread.php?t=67321

BTW: Remember that it is vital to make sure that your cat has its own food and water bowls, along with its own litter box in a room seperated from the other cats. Remember not to rush this process or to try and force them to interact with eachother, as this will likely bring about stress for your cat. Good luck.

Read the thread in that link and be aware that the process takes LOTS of patience! It took me a few weeks to introduce my cats. Then it was several months before my existing cat finally came to at least tolerate the newcomer.