Hi Liz,
I've been in a similar situation - my girlfriend and I have been together for about 2 1/2 years. She knew I had CF when we started dating, but didn't know very much specifically. To help her learn about it, I gave her a copy of "CF: A guide for patients and families" (which you should be able to get for free from your clinic). I think its a fair, thorough introduction to CF. After she read it, we talked about a bunch of stuff she had questions about.
We haven't had to deal with a lot of the long term stuff yet - we are very serious, and will have to figure out the infertility stuff eventually, but besides that, we take what comes are way, and work through it, not looking too far ahead into the future. She's been wonderful... she has learned Chest PT, and does it a few times a week for me (I use the vest most of the time). She's been with me at the hospital, and is in the process of getting carrier testing done.
I know that Christine isn't particularly comfortable talking about CF in the long term too - its uncertain, and it can be scary, and its easier not too.
I can see her point... what's there to say? When we have the really serious conversations every so often, I am very honest with her. I do not tell her I'll be around 40 or even 20 years from now, I tell her that I will do everything I possibly can to be here 40 years from now. We don't dwell on what could go wrong, because that doesn't prevent it from happening.
I think talking about CF is important - and every so often I make sure to check and make sure that Christine's ok with everything - my quarterly appointments offer me the opportunity do so, even if its just asking her to come along with me, or if she has any questions. I am pretty sure that as the one in the relationship with CF that I think about this stuff a lot more than she does, and for a long time felt guilty and selfish for being with her. I've realized that she's an adult, and loves me, and that its not my job to "save her from CF."
I hope this was somewhat helpful...
Chris
25 w/cf