I'm a photographer so I'm used to seeing boobs and bootie. I have nothing but praise for Carnival because if I wanted a "stuffy" vacation, I would go to the Hamptons or something.
My wife is very liberal and understands that we men "are" going to look at other women, just as women look at other men. Let a man walk by in a speedo, my wife and I will look at each other and literally read each other minds, like what did I just see!! The same happens when we see a large chest woman.
The F deck, although I've never been up there, is probably no worse than what your husband could find if he misspelled a website name and hit go!
Enjoy your Carnival Cruise, I know it was hard for us not too.