"We are speaking of this man."
Translation:Mówimy o tym mężczyźnie.
It should still be "Mówimy o tym panu" (We are speaking of this man/gentleman).
If you don't specify "pan" at all, that's Formal You. So your sentence is "We are speaking of you, sir".
Added "o tym panu", but I'm afraid that this will mostly be unaccepted, we've only decided to add such options veery recently.