when writing a story on line can i use these words?

What words and concepts are forbidden depends on the hosting site. I know you probably clicked on I Agree already, but go back and read their terms and conditions.

These terms would be fine on Archive of Our Own.

Sure, why not ?

Well, you just used those words online. And guess what. Nobody is arresting you, at least not in any civilized country. What the hell is wrong with you anyway?

You can use any words except 'District Nurse' which everyone knows is very rude indeed.