My boyfriend, and the 'other' man...?

If as you say, you love each other, then this is not the time to abandon him. Think of how your b/f feels, battling cancer and facing possible death. This is when he needs love and support the most. Instead of fighting over your uncertain future and feeling angry, this is when you should be drawing closer together and expressing your love for one another. You don`t know how much more time you will have together. He is probably frightened and more uncertain about his future than you are. If his prognosis was good for long term, then you could go ahead with whatever plans you had before he got sick, but since it isn`t, leaving him now in his most desperate time does not seem like the right thing to do. Do not let your daydreams of the other man come between you and your b/f at this time. Wait a bit longer to see where your b/f`s illness is heading. I wish peace to you both. Unless you have been there, cancer is a devastating, frightening thing to cope with. Try to be strong in this trying time, and stand by your man.