I want my fiancee to take my last name even though it sounds like a rude word
Why does she have to take your name?
Because I plan to be with her.
While it's traditional for a wife to take her husband's last name, you shouldn't just expect it of your fiance. It's inconsiderate to just expect her to change her name to something that will make her uncomfortable. Maybe you should consider taking her name instead.
And I should care what others think and change my last name? Ugh, fuck you.
But you should consider the way you've reacted to that idea, and put yourself in your future wife's shoes. If you wouldn't even entertain the possibility of changing your name, then you shouldn't expect her to have to do the same thing. It's fine for women to keep their maiden names, even in a lifelong marriage.