Ok, although I am not a CFer I still have my opinions about stuff like this so here it goes. You have to do what makes YOU happy. There are going to be a million times in your life when a majority of the people don't agree with what you think or do and they are going to "ride" you about it. Ultimately, you are the one who will live with all the decisions you make. Never in your life, or as the end is nearing should you have to say, "I wish I did this, I wish I wouldn't have listened to them...".
There are 2 ways to live your life (in my opinion). One is by quality and the other by quantity. If you live your life by the quality of things/people you wish to have, you might do some risky things (bunge jumping, sky diving, relationship with another CFer and risk getting yourself sick...) that might make you sicker, might make the "end" come a little faster.... but in those last moments you can reflect on all that you did in your life and be happy. Or, some choose to live their life by quantity, doing all they can to preserve their bodies and not taking too many risks. In the end, they may live longer, but they probably didn't do all those risky, fun and crazy things that they wanted to and many many times they have regrets. Then there are some in the middle who aren't one extreme or the other, but a combination of the two. I am the type of person who leans more towards quality (especially after dating and marrying my husband who has CF) than quantity. He lives his life the same way. If you don't enjoy yourself and do what makes you happy-what's the point?? That is how I live life. To each his own, but maybe it will help you feel better about your decision to do what makes YOU happy.
Sometimes the others who are "riding" you right now will come around, and sometimes they won't. All you can do at this point really, is tell them you understand/or that you hear their concern, but you are doing what is best for you and your happiness. It's ok to ask them to start keeping their opinions to themselves.
I wish you the best in this relationship,
Julie (wife to Mark 24 w/CF)