The sentence itself merely reports the situation, so it's a case of a use–mention distinction. You are mentioning an expression (or metaphor) someone else used. It would be normal to make the distinction clear by either using quotes or italics:
- He just gave me the biggest "fuck you" of my career.
- He just gave me the biggest fuck you of my career.
...depending on whether "Fuck you" was actually said or it's a metaphor for what was done.
I agree that the sentence is vulgar. But it may be reporting a derogatory or insulting [and vulgar] remark.